List of Generator Rex characters


The following is list of characters the appear in the cartoon series, Generator Rex.

Main characters

Rex Salazar

Rex Salazar is a 16 yr old half-Argentinean, half-Mexican, human E.V.O born to a family of scientists. Unlike other E.V.O.s, Rex can control his nanites at will, allowing him to cure other E.V.O.s of their mutations and use his nanites to create a variety of machines on his body and communicate with a variety of machines.
Rex is overconfident, impulsive, and typically, rebellious. He has a quick wit and is constantly making jokes. However, when Rex needs to defend himself, he doesn't hold back. He prefers to smash anything that gets in his way. Despite this, Rex has also shown a selfless side to his personality, as he has cured E.V.O.s even at his own risk.
Prior to the Nanite Event, Rex was critically injured in an industrial accident caused by a dispute between the many scientists about how the nanites were to be used. The scientists injected Rex with the original batch of fully programmed nanites, hoping to save Rex's life and to make the other scientists see that their ways were for the greater good. However, Rex's new abilities, courtesy of the nanites, only reinforced their beliefs. While Rex, Gabriel, and Caesar were able to survive the Nanite Event by sheer blind luck, Rafael and Violetta died as a result of the massive nanite explosion and Rex lost his memories.
Rex seemingly traveled the world, ending up as a leader of a small gang in Hong Kong and a lieutenant to a crime boss. A few years later, around age 14, Rex transformed into a giant bio-mechanical form and went on a rampage in Mexico. Providence sent a group of soldiers, including Six and White Knight, to contain the menace. After sustaining heavy damage, Rex crashed into a building and reverted to his human form, forgetting everything that happened before he turned full E.V.O. Six discovered him beneath the wreckage and helped him to safety. After that, he was accepted at Providence after he showed his ability to heal E.V.O.s. As Rex lived in Providence, he came to see it as his home and developed tight bonds with the people there, particularly Agent Six, Dr. Holiday and Bobo, openly acknowledging them as his family. After finding his older brother Caesar, Rex was glad to have found a family member, however, he admitted that he wasn't as happy as he thought he would be. He declared that the people in Providence - Six, Holiday and Bobo - were the ones he really had a family-like connection with.
Like all living beings on Earth, Rex has nanites bonded to him on a molecular level. Having activated nanites makes him an E.V.O., however, unlike most E.V.O.s, Rex has the ability to control his nanites at will, allowing him to do such things like communicate and control technology by interfacing it. He also control nanites from other E.V.O.s, curing them by extracting their activated nanites. However, some E.V.O.s, are incurables, having nanites that are completely resistant to curing. Additionally, Rex has a limit to how many nanites from cured E.V.O.s he can carry.
Rex's E.V.O. powers come in the form of "builds" a variety of machine enhancements his nanites can generate seemingly out of thin air. Even without his machines, Rex appears to have superhuman durability; on numerous occasions he's survived situations well beyond the limits of normal humans, like being thrown through walls. In addition, Rex was the only person at hand who could survive the fatal G forces of a 'space elevator' in the episode "Gravity". He is also, notably, shown to take several punches in the gut from a temporarily powerless Breach's more human pair of hands, displaying no signs of pain whatsoever.

Agent Six

Agent Six is a senior Providence agent and Rex's handler. His name came from the fact that he is the sixth most dangerous person in the planet. Due to Six's strict by-the-book personality, Rex goes as far as to refer to him as a "nanny, just more aggro". He always wears a green suit with a black tie and black sunglasses. As noted, Six likes to continually wear the same suit. It was shown that Six had brown eyes.
He was born and raised in an unnamed town in China, near Beijing, which would later be overrun by E.V.O. bugs in the episode "The Swarm". He was homeless at some point in his life and during that time "One" took him in and trained him. He later joined "The Six", a group of mercenaries, the six most dangerous persons in the planet that was led by One, and eventually, Six left the group. He later revealed that there was a time when he wanted to be number One and that he was well on his way until he met Rex. Six believed that his work for Providence was more important than his original work.
Six has an extremely stoic personality, often keeping a stern look on his face. Despite his emotionless exterior, he is a caring person deep down. It is implied that Six was not given the title of One because of the softer side of his personality, which made him less of a threat than the others. Six rigidly believes that orders are orders and that they must be obeyed even if one doesn't like them. However, Agent Six isn't without morals. For example, when White Knight was going to use a Bleach Bomb to stop zombie E.V.O.s from crossing the Brooklyn Bridge, Six removed the detonation key, effectively disobeying White Knight's orders. In an attempt to cheer Rex up, Six offered to buy Rex a few more days in Cabo Luna, despite the vacation not being authorized. Six also offered Rex the choice of leaving Providence. Additionally, he tricked White Knight into thinking he, Rex and Doctor Holiday would return on "The Keep". In "Six minus Six", after losing the last six years of his memories at a failure attempt of Caesar to restore Rex's memories, Six acts more like the mercenary he once was. He became more aggressive, cocky, merciless, irresponsible, sarcastic, as well as a bit of a loner. He is much more flirtatious towards Dr. Holiday and toward Five, to a lesser extent. After deciding to try to become the man everyone knows, Six started to act a little more like his responsible self but still acts more on the "mercenary" side of his personality.
He is skilled in martial arts. He wields a pair of "Magna blades" that can slice through most materials with ease and he stores them in his sleeves. These swords can also be used as a powerful magnet when joined together, forming a shape similar to a tuning fork. Six is also proficient in the art of knife throwing and still has formidable fighting skills when battling with a single katana. He is also very knowledgeable of Providence's rules and codes, most likely because of his by-the-book personality. He has peak human agility and speed. His skills are clearly seen when, after jumping out of a Providence carrier, he unsheathed his swords and performed a series of acrobatic feats. He sliced through boulder-sized chunks of debris in mid-air, jumping from each of them, and they wouldn't fall onto the civilians below—all before he touched the ground. Six's reflexes are fast enough that he can deflect point blank gunfire with his katana.

Bobo Haha

Bobo Haha is an E.V.O. chimp with the ability to speak. He is also Rex's sidekick and friend. He wears an eye patch and fez.
Bobo also claimed that before he was turned into an E.V.O., he was a helper animal trained to entertain children at a hospital. His owner was supposedly an eccentric philanthropist.
He is a fun-loving guy, always up to having a good time, and has a particular love for gambling. Bobo's good-hearted fun causes Providence to view him as a bad influence on Rex, since he encourages his rebellious tendencies. He is quick to fire his weapon in battle, preferring not to think about the variables. Despite close friends, he shows a general dislike for humans, whom he refers to as "sheep" because they seem to blindly follow the crowd.
Aside from his human-level intelligence and the ability to talk, he seems to be a completely normal chimpanzee. He also wields a pair of rather large laser pistols in combat. He is apparently knowledgeable of codes used by Providence, information about locations, and is able to fly a variety of military grade aircraft as well as use a variety of military grade weapons. His swinging, balancing and jumping capabilities are that of a typical jungle-variety chimpanzee. Bobo has super-human strength, like a normal chimpanzee. Despite his attitude problems and gangster personality, Bobo Haha has shown himself to be techno-savvy and intelligent enough to create a fully functional android to pose as him while on his "Bobo-time".

Rebecca Holiday

Rebecca Holiday is the lead scientist for Providence, a position she earned due to her expertise in nanotechnology. Along with Agent Six, she is responsible for taking care of Rex. She takes her job very seriously, constantly monitoring Rex to ensure his safety.
Her younger sister, Beverly, became an incurable and extremely dangerous E.V.O at thirteen. In the early days of Providence, Holiday served as a medical assistant to Dr. Fell. It is implied that Holiday joined Providence in exchange for the guarantee of her sister's safety. However, she was against Providence's protocol for handling E.V.O.s, which was to contain or destroy them. Although she had no authority in the matter, she believed that finding a cure was another alternative.
On the day that Six found Rex and his ability to cure E.V.O.s, he showed Rex to Holiday, who was overjoyed with the discovery, but promised Six not to tell White Knight, who, at this point, only intended to kill E.V.O.s. Unfortunately, White Knight was mysteriously able to get her to confess, and locked her in a cage to prevent Rex's dissection from being stopped. Later, Dr. Fell was fired by Providence following his attempt to dissect Rex and was soon replaced by Dr. Holiday.
Holiday is the polar opposite of Agent Six, as she is much more in-tune with her emotions. Although she can be short-tempered and stubborn at times, she is a deeply caring person. Her stubbornness can also lead to determination. Holiday is also not afraid to speak her mind in front of her superiors, especially when she believes she has a better solution to a problem. She is also a very empathetic person. She's frequently expressed concern over the fact that Providence sees Rex only as a weapon, and not as a sixteen-year-old teenager. She repeatedly tries to convince Six to try to relate with Rex, as she understands what he goes through with his amnesia and the pressure put on him by Providence.
Rex frequently flirts with Holiday despite the fact that she is much older than him. While she is widely aware of his crush on her, she mostly ignores him. Later, Rex realizes this fact and stops.
Six, on the advice of Rex, later asked her out on a date, which she gladly accepted. Following Six's memory loss, Holiday was a little unnerved by his more aggressive romantic overtures, though it is confirmed in further episodes that her feelings toward him have remained the same. This is evident in the season three episode, 'Ben 10/Generator Rex : Heroes United,' when she kneels beside Six, who is in a comatose state, and kisses the glass of the chamber he is in.
Holiday also exhibits adequate fighting ability and a strong capability with Providence weapons, evident when she dove in front of gunfire aimed at Rex and Six while fighting E.V.O.s in Abysus. In the episode 'Payback,' Six handed Holiday a Providence gun, to defend herself against the Pack and Van Kleiss. In the Petting Zoo, Holiday is cornered by Skalamander, but being resourceful, she unleashes her sister, Beverly, who chases Skalamander away.

Noah Nixon

Noah Nixon is a human and Rex's best friend. In the beginning it was revealed that he is an agent sent by White Knight to befriend Rex and subtly influence his decisions to make him more compliant. Noah eventually revealed to Rex his status as a covert agent and they became friends on open terms.
Being best friends and having many similar interests, Noah isn't too different from Rex. Besides being very competitive against one another, Noah has shown to be more of a mature and responsible teenager than Rex. Although his normal job was to keep an eye on Rex as a spy for White Knight, Noah seems to do it perfectly fine on his own on any occasion, and tends to be a voice of reason. He also displays a bit of loyalty and bravery since he is ready to fight whenever trouble brews around the two. Noah is a normal human: however he has taken a kick-boxing class in and he's received basic Providence training. On several occasions, he has been shown proficient enough with Providence weaponry. Noah is shown to be a star Ping-Pong player, short of Rex who enrolled in his school for one week. Noah's main love interest is Claire Bowman, a girl that he originally asks to the Prom. She is only willing to go with him if he can find a date for her clumsy friend, Amy, and so Rex becomes his wingman. In the episode 'Haunted', Noah's feelings toward Claire are confirmed. Rex sets up a date to watch a scary movie with the two girls, Noah and himself, but this ultimately fails when both girls cling to Rex. Further into the date, when in a haunted house supposedly 'rigged' by Rex's brother Caesar, it is discovered that an actual 'ghost' E.V.O. is responsible for some of the occurrences. When the E.V.O. attacks, Rex pushes Noah and Claire into an elevator, but the E.V.O. slams into the doors and crushes them shut. In the elevator, it is revealed that Claire is claustrophobic, and so Noah comforts her by talking to her and keeping her calm. When Rex eventually opens the doors, Noah has his arm around Claire's shoulders. Towards the end of the date, Noah and Claire almost kiss, but are interrupted by the presence of Caesar, whereby Claire and Amy begin to question him about the technology he used to create some of the illusions.

White Knight

White Knight is the leader of Providence. He also is the only known nanite-free being on the planet: he almost always stays in his white sterile office, communicating his orders only through two-way screens. He has a Mysophobia-like fear of nanites, he doesn't want to touch or even be near E.V.O.s because he fears they'll infect him with nanites.
At least 6 years ago, White and Six were working together as mercenaries. Most likely at Six's suggestion, the duo went to work for Providence. Several years later, White and Six were called in to halt the rampage of a giant Bio-Mechanical E.V.O. Much to White's shock, Six had rescued a young Rex in the area where the E.V.O. had rampaged, and would later discover that they were one and the same. The additional discovery that Rex had the ability to cure other E.V.O.s prompted White to kidnap him and bring him to the head of R&D Dr. Fell to have him reverse-engineer Rex's powers. Six and White got into a fight over the life of Rex which had accidentally overloaded the molecular disassembling chamber that was being used to study him. White rescued Six and brought him to safety but he was caught in the destruction of the machine. Rex deactivated the machine before it killed him, and the accident stripped him of his nanites. White Knight was then promoted to leader of Providence. His nanite-free condition made him "the perfect poster boy for the operation", as he put it, but as a consequence he was trapped in a sterile nanite free environment for the rest of his life to prevent reinfection with them. However, despite saving his life, White would never forget the monster that Rex was when he was found and began construction of a Weapon Zed Hazmat suit to kill him if he ever turned back.
He is cold and ruthless when it comes to achieving his goals: White seems to favor violence to get the job done. He views most of his soldiers, including Rex, as expendable weapons. When his soldiers act out of line, he's not above threatening them. He even threatened to eliminate Rex if Six could not learn to control him better. As a boss, White Knight is tirelessly difficult-to-please, demanding and critical and verbally rejects all or essentially all objections to his leadership style. White Knight has also been shown to be manipulative. He hired Noah to spy on and influence Rex: although Rex eventually discovered the truth about Noah, he still decided to be Noah's friend. This implies that White Knight is trying to indirectly control Rex's life. White Knight has both a fear and hatred of E.V.O.s and nanites. Over the years, he's seen that nanites typically turn humans and animals into mindless, rampaging beasts: thus, he doesn't trust anything with nanites, namely every living thing on the planet. Furthermore, his own lack of nanites makes him feel like he's the only person on Earth that can be trusted. At times, he demonstrates a slightly sadistic behavior toward E.V.O.s.
On one occasion, White Knight emerged from his office wearing a pressurized suit that protected him from all nanites. It also greatly enhanced his strength, reflexes and agility tenfold, and had limited self-repairing capabilities. Also it was revealed that he had constructed a giant mech-like robot, specifically designed to combat E.V.O.s, specifically Rex if he ever went out of control. The robot is piloted by a person inside. It has a large arsenal of weapons, greatly enhances White Knight's strength, and has flight capabilities. However, it was destroyed after battling Rex, and it was rebuilt before he was replaced as head of Providence by Black Knight.

Caesar Salazar

Caesar Salazar is Rex's older brother and one of the surviving scientists of the Nanite Project.
Alongside his parents, Caesar started the nanite research team in Abysus. During the research, the scientists divided into groups, each having different ideas about how to use the power coming from the nanites. During the Nanite Project, Caesar created two Artificial Intelligences that later went rogue and threatened all life on earth; the decontamination program ZAG-RS and the control nanite Alpha. Due to the unfortunate event, ten-year-old Rex was gravely hurt and only an infusion of nanites could save him. Yet the successful operation did not convince the others to change their plans. One of the scientists sabotaged the project, which caused a massive explosion, and it was Rex's new powers that saved Caesar and Rex during the Nanite Event. Van Kleiss claimed it was Caesar who caused the event. Just before the explosion, he fled to his research pod and activated its subspace engines to get away. The engines were super charged and launched the pod into orbit at super speeds. The speed he was traveling at was so great that in the fifteen minutes it took to take control over the machine, five years had gone by on the rest of the planet.
Caesar's personality is akin to that of a mad scientist, coming off to Rex and the others as a tad out of whack from reality. Yet he seems to be aware of his own eccentricities as demonstrated when Rex asked him. Although having no amnesia, Caesar has an information gap due to his five-year absence in sub-speed caused by the explosion blast at the Abysus research facility. He occasionally talks off subject, easily distracted and does not seem to listen when spoken to directly and is sometimes forgetful in daily activities. Caesar is also very upbeat, curious and quite over-protective of his younger brother. In fact, it seems some of Caesar's less "weird" traits are shared with Rex, such as his sense of humor and loyalty. He seems to be fearless, as long as science is involved, as he was not afraid of the mutations due to his work on nanites. As he had previously mentioned, he and his colleagues had expected mutations, but nothing like the present E.V.O.s. He stood in front of many without worrying about being harmed. Thus far, it seems that he is generally not afraid of anything, as made apparent by not only the E.V.O. situations, but the way he barged into Providence without prior worry. Aside for science, he also isn't afraid to go up against stronger men like Agent Six or Hunter Cain to defend Rex even though he is not technically a combatant or Rex doesn't necessarily need help.
In "Black and White", Rex encounters César during White Knight's raid, where he has been put in charge of starting the second Nanite Event in the hopes of restoring Dr. Gabriel Rylander. He had tried to explain to a positively angered Rex, that he had only started the original Nanite Event in an attempt to save the world.
In "End Game" Pt. 2, it is finally revealed that Caesar along with his parents were, in fact, the saboteurs of the Nanite Project, as they wanted to keep the Consortium from gaining the Meta-Nanites for their plan of conquest.

Antagonists

Van Kleiss

Van Kleiss is the primary antagonist of the series. Van Kleiss appears to know quite a bit about Rex, and knows what caused the nanite incident. He saw the nanite incident as the dawn of a new age for humanity, and seeks to create a planet populated solely by E.V.O.s. Like Rex, he is able to control his nanites; unlike Rex, however, his mutation is unstable and requires a constant supply of fresh nanites, extracted from other E.V.O.s, who are petrified in the process. He does this with needles on his gauntlet that go into the E.V.O. With his E.V.O. enforcers, the Pack, he has established a domain called Abysus at the original site of the nanite explosion, and has seeded nanites for miles in the area. As a result, he can control everything in his sphere of influence, and even regenerate completely from the ground if his body is destroyed. He has a highly extensive knowledge of the nanites, having apparently worked on or been familiar with the experiment which released them, and about Rex's past. He is killed in "Dark Passage" while attempting to secure Dr. Gabriel Rylander's nanite laboratory, but is resurrected in "What Lies Beneath" by his followers and Rex, to prevent Abysus from becoming unstable. Rex cures him shortly thereafter. In doing so, however, he gives Van Kleiss the means to study his nanites, which Van Kleiss then uses to gain the power to create E.V.O.s by touch, leaving a handprint-mark. E.V.O.s created by Van Kleiss are extremely unstable, meaning that the transformation becomes permanent if not cured within a time limit. Curiously, in the first season finale "Payback", when Van Kleiss drained Rex of his active nanites, Rex wasn't petrified. This was most likely because Van Kleiss was not able to absorb the Omega-One nanite that Dr. Rylander had injected into Rex, thus protecting him from becoming petrified like Van Kleiss' other victims. In "Lions and Lambs", Van Kleiss attaches a device to Breach in a plot to travel through time. When Breach ends up sending Van Kleiss away in a bright golden-colored time portal, Breach starts to disappear as Rex is mysteriously transported six months into the future where Providence is run by a woman called Black Knight. In "A Brief History of Time," it is later revealed that Van Kleiss was sent 4000 years into the past and began working to return to the present all the while pursued by an unknown entity that he believed sought to destroy him. His journey took him through multiple eras, such as the Roman Empire and an unknown Japanese era. When he is found by Rex and Providence, he has grown a beard and seemingly been driven to the brink of insanity by his ordeal. He was knocked out by Bobo Haha and taken away by Providence. He also has unknown connections with Black Knight when she appeared where Van Kleiss was placed.
In "End Game" Pt. 2, it is revealed that Van Kleiss had the same objective as the Consortium and wanted power to himself and believed that the nanites could help achieve that. He also murdered Rex's parents once they caused the explosion after discovering the same thing. During the final cure, he is dragged by Breach into one of her wormholes. His fate is unknown.
The name Van Klei is Dutch for "Of clay," which could be a reference to his original nature/earth-controlling abilities.

The Pack

The Pack is a group of E.V.O.s that serve Van Kleiss. Its known members include the following:

Biowulf

Biowulf is a blue-armored, white-haired, werewolf-like E.V.O. with enormous claws, who is fiercely loyal to Van Kleiss, whom he calls "master." Due to Van Kleiss' powers being limited to his native soil in early episodes, Biowulf initially acts as the Pack's de facto leader in the field. He is captured in "Payback" during the assault on Providence's base, but is apparently freed by Breach. He is extremely loyal and faithful to his master, despite Van Kleiss tiring of his constant failures. In "Assault on Abysus," Biowulf is shown to have taken over the pack after what happened to Van Kleiss. He and the other E.V.O.s that served Van Kleiss end up helping Rex find the Meta-Nanite at the same time when Black Knight's men attacked Abysus. Biowulf and Circe managed to buy Rex some time to get away with the Meta-Nanite resulting in their capture.

Skalamander

Skalamander is a large humanoid lizard-like E.V.O. with crystal spikes growing out of his body, four short stubby legs and a crystal club growing out of his left arm. His head appears to be permanently twisted to its side. He can fire spikes out of his club or grow it into a shield. In "Payback," Skalamander took part in Van Kleiss' attack on Providence. He had Dr. Holiday cornered until she unleashed her sister on him. He was presumably captured and later rescued by Breach. In "Assault on Abysus," Skalamander and the E.V.O.s that served Van Kleiss end up assisting Rex into finding the Meta-Nanite at the same time when Black Knight's men attacked Abysus. Skalamander ends up captured by Black Knight's men.

ZAG-RS

ZAG-RS is a sentient and autonomous, self-aware artificial intelligence/multi-agent system whose goal is to destroy the nanite infestation of Earth. Its origin and motives are initially left mysterious, but it is able to exert control over the nanites at very short ranges. It makes several different attempts to achieve its goal. Its methods have in common that they would also destroy everything infected with nanites, including all organic life on Earth, a prospect to which ZAG-RS is apparently indifferent. The AI has no permanent form, being a program capable of uploading itself into computers and autonomous devices. It speaks in a synthesized female voice. In "The Architect", ZAG-RS attempts to transmit a self-destruct command to all nanites on Earth. Rex manages to destroy its broadcast antenna, but the AI escapes by uploading its program to a new location. In "Gravity", ZAG-RS infiltrates a Providence space station in order to secure a strain of nanite-disabling nanites that it had secretly helped develop. Rex and Dr. Holiday are able to deorbit the station, destroying the nanites. In "Written in Sand", Rex and Van Kleiss separately arrive in a desert location to investigate a mysterious sandstorm, and find themselves trapped in a network of nanite-annihilating tunnels created by ZAG-RS. Van Kleiss reveals that ZAG-RS dates to the Nanite Project, having originally been a decontamination program designed by Caesar to contain and eliminate stray nanites. In addition to the tunnels, ZAG-RS had spent the time since its fall from orbit constructing a giant robotic form for itself, which Rex and Van Kleiss fight and defeat. Later, Caesar admits that ZAG-RS had indeed been his creation. He brings its damaged hardware back online so it can be interrogated, but while it recognizes Caesar, it appears to have been reformatted and its memory wiped. After Rex mocks the AI for its "GPS lady voice," Caesar reveals that he had modeled ZAG-RS' voice after that of their deceased Mexican mother Violetta.

Agent Weaver

Agent Weaver is a former member of Providence stationed at the arctic "Paradise" base where he was the chief technician. He and his crew were revealed to be traitors who were reactivating and selling nanites to Van Kleiss. In "Frostbite", he accidentally turned himself into a monstrous 50-foot, tentacled E.V.O. after he unintentionally destabilized the containment unit. When Rex was unable to fully cure him due to the excessive amount of nanites he absorbed, Weaver was defeated by Agent Six and knocked down when Dr. Holiday rammed the ship into him. In "Basic", it was revealed that Weaver was extracted from the arctic and locked up in the E.V.O.-Fighting Cage at the Providence Training Camp. Due to a malfunction caused by a jealous Kenwyn Jones, Weaver and the other E.V.O.s got out. Weaver remembered Rex during his fight with the E.V.O.s. Rex managed to knock Weaver back into the pit.

Hunter Cain

Hunter Cain is an E.V.O. hunter who despises all E.V.O.s under all circumstances as he went insane after his wife became E.V.O. He uses a weapon loaded with special bullets that forces Nanites to self-destruct, vaporizing an E.V.O in an instant. First appearing in "The Hunter", he disrupts Rex from curing an E.V.O. and damages Providence's reputation by claiming that they lied to the public for years. Hunter Cain states E.V.O.s are created by diseases spread from person to person rather than the Nanites. Rex is soon defamed after being attacked by civilians and injuring one accidentally. Later in the episode, a swarm of Phantom-like E.V.O.s attack the docks, which Cain's private army dispatches. After Rex arrives and fights Cain one-on-one in a secluded area, the Hunter reveals that he had cloned the Phantom E.V.O.s to create his army and prove Providence's ineffectiveness. The whole statement was caught on News. After a rough battle, Rex ties up Cain and leaves him for Providence to arrest, and his not-so loyal army disbands at the end of the episode. Hunter Cain returns in "Night Falls" along with a new army where he is hired by Mayor Esteban to dispatch Rex's adoptive family who suddenly turn into Werewolf-like E.V.O.s during the night. Hunter Cain informs Rex that he ran out of his special bullets replacing them with regular ones that "hurt just as bad." During the skirmish between the E.V.O.s and Cain's army, Hunter Cain reveals that he escaped Providence using "cold hard cash" as "not everyone in Providence are E.V.O. lovers" Hunter Cain is eventually chased off by the Werewolf-like E.V.O.s, and Rex remarks that they will be ready for his return. In "Enemies Mine," Hunter freed and formed an alliance with Gatlocke, Valve, and NoFace to find and kill Rex. He, along with his three cohorts, was trapped in a large dome-shaped barrier created by Rex's surplus nanites.

NoFace

NoFace is a supremely powerful and vengeful faceless E.V.O. with the ability to communicate with intelligent E.V.O.s and control the less intelligent ones. During the nanite event, the Gulf Stream funneled a huge amount of active nanites into the city of Kiev, Ukraine, transforming nearly all that lived there into extremely powerful E.V.O.s. Among them was their current leader, NoFace. In response to the chaos, all humans were evacuated and the city quarantined via a massive one-way spherical force field. In "The Forgotten", NoFace spotted Captain Callan's ship and shot it down, forcing Calan and his crew to try and repair it, hoping to use it to escape the city with the data rod containing important information to Providence. NoFace knew they would send in more ships to retrieve the rod and would continue to shoot them down until he had the means of escaping. His plot failed due to Rex's interference and a self-destruct device Calan had secret planted in the ship he repaired. NoFace has alluded to something called "the before", and during a battle with Rex he said "You are not the before". It is currently unknown what this means, it might mean the people before their transformations. In "Alliance", Van Kleiss and the Pack infiltrated the Bug Jar in order to form an alliance with NoFace. After Circe captures Rex, NoFace agrees to join Van Kleiss if he is allowed to humiliate Rex. Van Kleiss agrees, and NoFace takes Rex to an arena, where he severely beats him up. However, when Van Kleiss refused to let NoFace kill Rex because he still needed him "alive", he and his E.V.O.s attacked the Pack, severing ties with Van Kleiss and the Pack.

Quarry

Quarry is an E.V.O. crime lord who is made of rock. He would hunt down and force E.V.O.s like Tuck, Skwydd, and Cricket to work for him through having gathered a massive criminal empire. In "Rabble", he learned of Rex's return from his enforcer Knuckles after Rex drained him of his nanites. Quarry had to dispose of Knuckles after that. He later revealed that once upon a time Rex was his top lieutenant and he traded Tuck, Cricket, and Skwydd, whom he had befriended, for his freedom. His defeat came at the hands of Rex, who now had no idea about his past including his dealings with Quarry and showed no mercy in defeating him, in the process regaining the trust and friendship of the three E.V.O.s he had betrayed. He is sneaky and deceitful and some say he lied about Rex's betrayal to keep his power. Rex managed to defeat Quarry and his loyal E.V.O. servants and he was then arrested by Providence. In "Hard Target," Van Kleiss has Breach spring Quarry from his imprisonment only for him to trick Breach into telling him about the dangerous ultimate weapon Van Kleiss wants him to steal and steals it for himself. Rex defeats Quarry and trades him to Breach in exchange for Circe, who Breach had kidnapped earlier. Breach takes Quarry to Van Kleiss, and he can take the blame for her "failure." In "Remote Control," Quarry was shown to have some cybernetics holding his rocky body together after what he had endured at the hands of Van Kleiss. When Providence began to promote its E.V.O. Control campaign, Quarry returned to Hong Kong and defeated the Providence soldiers where he confiscated their technology, and he can control Tuck, Skwydd, Cricket, and other E.V.O. hiding out in Hong Kong. This time, Rex was able to defeat Quarry by shattering him. What was left of Quarry was picked up by Providence who also managed to obtain the technology that Quarry was using to control the E.V.O.'s into doing his bidding.

Gatlocke

Gatlocke is a cyborg who is a leader of a group of modern-day pirates known as "The Anarchists". In "Badlands", he is introduced spying through an eyeglass down a canyon to an unstable nanite shipment below. After a short pep speech, he gives the order for everyone to attack. With Rex nowhere in sight, Gatlocke and his thieves succeed in taking the convoy with little trouble, not realizing until they're back at base that the "unstable nanites" they stole were actually toilet paper, a decoy. Gatlocke loses his temper, but a minion reveals that there's another truck; Rex's, which actually has the unstable nanites on board. His minions quickly locate Rex and his crew, right where the last battle's carnage remained. Gatlocke introduces himself to Rex and tries to convince him to join their group, appealing to his hate of rules. He reveals his blades to further "persuade" him, which backfires. After a very short tussle, Rex and crew jump back into their truck. Then the chase begins. Eventually, Gatlocke crashes Rex's truck, then begins to approach him, giving him a rather merry hug. He asks again for the unstable nanites, saying that he'll split the profits with Rex "evenly", but Rex refuses. After some more bantering and a poor escape plan, Rex throws a can of flat soda claiming that it contains nanites ready to explode which gives him a short head start. Gatlocke and crew catch up with Rex yet again. Rex and Gatlocke begin a rather evenly-matched one-on-one battle on top of the convoy that Gatlocke and his gang hijacked earlier. Gatlocke shoots with his energy canon and loses that hand near the beginning of the fight, but he takes out Rex's Smackhands without much trouble. The battle continues, now with Rex's BFS versus Gatlocke's arm blades: they more-or-less end up at a stalemate. Gatlocke attempts to have Rex join him yet again, which is refused. After some more bickering, Gatlocke states that Rex and he are the same. Rex refutes this with a single fact; that Gatlocke can't fly. Gatlocke, convoy and all, go hurtling down a ravine while Rex escapes on the Boogie Pack. Gatlocke manages to climb back up the ravine with still one hand missing. He demands the unstable nanites, and Rex throws it to him, recently learning and stating that its harsh care made it useless. At this, Gatlocke utterly snaps, screaming at Rex and running at him: receiving a Smackhand to the face. He seems mostly unfazed as Providence soldiers carry him off, most likely to imprison him.

Black Knight

Black Knight is the next Providence leader after White Knight rebelled against his superiors in the Consortium. When she took over Providence, she started to run things very differently from the way White Knight had. She believes in controlling the uncurable E.V.O.s as rather than trying to cure them. This way, she and her superiors would turn them into little more than obedient slaves. At first, she tries to work with Rex instead of trying to control and manipulate him. But when it becomes clear Rex is against what she and his older brother are doing, she orders César to use the mind-controlling and brainwashing machine on his younger brother. Before this can be done, Rex is saved from Black Knight's men by Agent Six and Dr. Holiday. In "Riddle of the Sphinx", Black Knight obtained some hieroglyphics which mentioned Van Kleiss' involvement in the creation of Gharun Set. In "Black and White", she and César planned to start the next Nanite Event in a plan to restore Dr. Gabriel Rylander. During White Knight's raid, she ended up fighting White Knight in the room that used to be White Knight's office. White Knight did obtain a confession from Black Knight that he might use if he is brought before the Consortium. In "Deadzone", Black Knight and her henchmen failed to obtain a nerdy human E.V.O. called Fitzy Feakins to make E.V.O. capturing much easier and more simpler. This forced her to take much more aggressive action against Rex. In "Assault on Abysus", Black Knight promotes her E.V.O.-Controlling campaign on TV by capturing any E.V.O.'s that are still free. Her men even managed to capture Tuck, Skwydd, and Cricket when they searched Hong Kong. Black Knight leads her forces to Abysus where the Meta-Nanite is held. Although Rex managed to get away with the Meta-Nanite, Black Knight's men managed to capture Circe, Biowulf, Skalamander, and the other unnamed E.V.O.s that served Van Kleiss. In "A Brief History of Time", it is shown that Van Kleiss knows about Black Knight when she arrived in the area where the Providence agents had placed him upon apprehending him. In "Target: Consortium", Black Knight appeared before the Consortium wanting to join them. When Consortium member Vostok had doubt on her nanite project, Black Knight ended up killing Vostok. In "End Game" Pt. 1, Black Knight gains some E.V.O. abilities upon obtaining the Meta-Nanites. In "End Game" Pt. 2, a flashback of Rex's shows her in a lab coat at the nanite research facility, implying that she was directly related to the first Nanite Project. Like the other members of the Consortium, Black Knight gets away as she and the Consortium are unaffected by Rex's planet-wide nanite curing. However, it is presumed that she and the Consortium were captured by Providence off-screen.

Valve

Valve is a samurai-styled biker and a dealer of an altered form of nanites which can link a person to technology. He sold some of them to some local bikers who would be kept in contrast with their bikes or else the nanites would kill them. He used the nanites on himself, and he can merge with his motorcycle. When Rex traced the nanites that killed his biker friends back to Valve, he challenged Valve to a race to determine the fate of the altered nanites. During the race, Rex managed to defeat Valve. When Valve tried to kill Rex, he easily defeated Valve with his smack hands.

Gharun Set

Technically the first E.V.O. ever created, Gharun Set was an ancient Egyptian created by Van Kleiss when Breach sent him back in time to ancient Egypt. somehow being able to create a nanite production chamber, what Set calls the "engines of life" Van Kleiss infused them into Gharun Set, changing his appearance into a dog-headed mummy-like humanoid with an eye in the center of his chest. Gharun Set's nanites give him extrodinary powers even when compared to other E.V.O.s. These powers seem to be relating to animating inanimate or dead objects such as mummies and even the great sphinx which turned into a monster under Set's control. Set's nanites gave him great longevity but eventually began to die during his awakening, causing him to turn to dust. Van Kleiss told Set about Rex and how neither of them belonged in the world. In "A Brief History of Time", it was shown that Gharun Set had helped Van Kleiss build his time machine which he used to get back to the present.

The Consortium

The Consortium is a powerful organization which supports Providence and are the superiors of Black Knight. Little is known about this organization, but they seem to provide funding for Providence and the Nanite Project. In "End Game" Pt. 1, the Consortium gets injected with the Meta-Nanites, enabling them to gain different, powerful abilities. As of "End Game" Pt. 2, the Consortium gets away upon Rex doing a planetwide E.V.O. curing making them unaffected by it, but is presumed that they were captured by Providence off-screen.

Reddick

Reddick is a real estate agent and construction associate who is a member of the Consortium. When merged with a Meta-Nanite, he was transformed into a gray hulking robot E.V.O. with the ability to control gravity and fly.

Roswell

Roswell is a southern businessman who is a member of the Consortium. When merged with the Meta-Nanite, he became a red and blue-armored E.V.O. with powers that enabled him to control both fire and ice.

Sir Anthony Haden-Scott

Sir Anthony Haden-Scott is a member of the Consortium. After being injected with the Meta-Nanite, he became an E.V.O. with dark gray armor with orange lightning strikes on it and had the ability to manipulate matter and energy as well as the ability to fly.

Vostok

Vostok is a black market financier and KGB operative who is a member of the Consortium. He was with the Consortium when Black Knight brought about her plans to restart the Nanite project. Vostok had some doubts about Black Knight's plot causing Black Knight to kill him when they were alone. Black Knight told the other Consortium members that the enemy was responsible for Vostok's death.

Alpha

Alpha was created by Caesar to control other nanites as a sentient being, but its energy/nanite body was unsustainable. Alpha tried to make mechanical bodies to sustain itself and that failed, so instead it tried to use living organic bodies as hosts.
Due to this, Alpha was sent to a parallel dimension, the Null Void, by Caesar, who mistakenly thought he had sent the nanite to an empty pocket dimension when in fact it was a prison for alien criminals. Later, Alpha returned as its normal form—an energy figure shaped as a human. Caesar came to send it back to the Null Void, but was blocked by Ben Tennyson, who thought Caesar was attacking Ben and Rex. Alpha asked for Caesar's help, but Caesar refused. Caesar took Ben and Rex in his mobile lab and explained what Alpha was and how he was trying to return him to the Null Void, but when Alpha attacked the lab Caesar exited alone in an escape pod, leaving Ben and Rex in the exploding remains of the lab to face Alpha. However, they escaped by Ben saving Rex using Cannonbolt.
Alpha then attacked the Petting Zoo at The Plant, where he intended to absorb more nanites. He was attacked by Dr. Holiday, Rex, and Ben, where he escaped, not being strong enough to take them all on, but not before learning that Rex's body sheltered an Omega-1 Nanite.
Eventually, Alpha was located at the Bug Jar, where Rex, Ben, and White Knight went to go stop him. They quickly discovered that Alpha had absorbed the entire nanite population, growing into a 20-foot tall beast that was set on absorbing Rex's Omega Nanite. Eventually, it even hacked Ben's Ultimatrix due to the nanites it absorbed upon his arrival. It created its own Ultimatrix and transformed into EVO-like versions of several of Ben's forms, specifically Heatblast, Fourarms, and Humongousaur. Rex absorbed all of the nanites Alpha used to make his Ultimatrix, but wasn't strong enough to stop Alpha from taking his Omega-1 nanite. Alpha evolved into a 100-foot tall form with crab-like legs and called itself "Alpha-Omega". He then proceeded to destroy the city, but was ambushed by Rex and Ben when they merged using Upgrade, greatly enhancing Rex's abilities. Eventually, Rex used Ben as Cannonbolt to attack the protected Omega nanite, and he was morphed into a nanite-cloud form.
Rex then absorbed all the nanites Alpha had taken from the inhabitants in the Bug Jar and reduced Alpha to a small nanite sphere made out of dense matter. Caesar then appeared and opened another dimensional rift to the Null Void. Ben transformed into Upchuck and swallowed up the Alpha sphere and left for his universe. Alpha is last seen in the Null Void, breaking out of his sphere.

Recurring Characters

Diane Farrah

Diane Farrah is a newswoman who hosts a news program called "Ultimate Exposure". She appears regularly at the places where Providence fights EV.O.s, as a hostess of her program or when she's having interviews with people involved with E.V.O.s.
Diane arrived at Providence with permission to interview Providence, it is implied by White Knight that she forced him to get access to Providence. Diane appears to have a one-sided crush on Six, as shown when she briefly flirted with him. After fully interviewing Providence, she edited the documentary and made it all about Agent Six, calling him Providence's secret weapon and "a man of many mysteries".

Breach

Breach is a four-armed human E.V.O. girl. Using her larger arms, Breach can tear open space and time, creating wormholes. Her portals also seem to have a plane, as those who go through them can stand within the portal without having to step out on either of the linked locations.
She also has a pocket dimension where she stores the "toys" or "shiny things" that appeal to her, including Rex. When they are "broken", "out of place" or "no good", she opens a portal and throws them away in the real world. The pocket dimension is the entire city of Greenville, Ohio, which disappeared when Breach took it. The city is her entire "dollhouse" in which she plays with her toys and keeps everything neat and tidy.
Breach is rather childish, sensitive, and lonely. She yearns for things such as people, E.V.O.s and objects to overcome her loneliness, treating those that attract or amuse her like toys and putting them in her creepy "dollhouse" pocket dimension.
When Breach's powers are enhanced, she can open golden time portals at will. By opening them in time, she possesses the ability to either take or send things from the past or future. The downside to this is that when her powers are enhanced, she is under the control of Van Kleiss' technology, giving him full control over whether or not he wants her to be in control of her abilities.
In "Lions and Lambs", after suffering incredible physical pain while participating in one of Van Kleiss' experiments, Breach was confronted by Rex, during which he asked her why she was willing to tolerate her master's abuse. Although she initially seemed unconvinced, Breach saved Rex from the Pack and they escaped together through one of her portals. During this time she displayed a keen interest in Rex, even taking him to different places that comforted her in the hope that he would learn to understand her. After spending some time alone together and before hugging, she expressed the desire to be with him forever, and at the very least considers him to be a friend.

Circe

Circe is a human-looking teenage E.V.O., who is Rex's main romantic interest throughout the entire series.
Circe first met Rex in "Beyond the Sea," at a beach resort in Cabo Luna by accident during a volleyball game. Although slightly annoyed at the encounter, Rex later convinced her to hang out with him, and she became considerably warmer and friendlier towards him, as she seemed to really enjoy his company and time with him and liked him very much. Later, Circe had to defeat a gigantic Sea Monster E.V.O. as part of an initiation test to become one of The Pack. Although she needed Rex's help to defeat the creature, which she then gladly accepted, Van Kleiss still allowed her to join anyway; both because of her uniquely musical, hypnotic abilities and mostly intending to take advantage of the genuinely pure and strong everlasting romance blossoming between her and Rex to try and lure him over to his side.
Circe does indeed have real feelings for Rex and is shown to be much more merciful and lenient towards him than any other members of the Pack as evidence of how much she cares about him. She also is seen with many expressions of guilt, sadness, and regret for working against the one guy she truly cares about with all her heart. She considers Rex her only real friend she has had since becoming an E.V.O.
In "What Lies Beneath," she admitted to Rex that as much she really cared about him, she could not abandon either the Pack or Van Kleiss as they had taken her in when no one else would. She held his hand in an affectionate way, smiled sadly, and thanked him for saving her life. She had said that being on opposite sides "kept things interesting."
In "Alliance," when Van Kleiss threw an unconscious Rex at the mercy of the vengeful NoFace, she realized Van Kleiss for what he truly is: a ruthless dictator who sees all of his minions as a means to an end. Afterward, she and Rex went their separate ways. She rode off in a Providence motorcycle, minus the tracking device. It was also hinted that Van Kleiss had something on Circe that neither she nor Van Kleiss has revealed, hence why she continued to work for him despite his questionable aggressive methods. She later quit the Pack and traveled to Hong Kong, China, to join Rex's old E.V.O. street gang, where she got along well with Skwydd, which greatly concerned and made Rex really uncomfortable. She also seemed to enjoy having playful hand-to-hand combat training with him. When Rex had said that he was "okay" with her and Skwydd being an item, she firmly assured him that she and Skwydd were friends on a platonic level and nothing more.
Circe has the E.V.O. ability to project destructive hypersonic sound blasts from her mouth. As her name states, Circe also can mystically lure other E.V.O.s towards her with a hypnotic melody. However, use of this ability is limited, as using it for long periods can tire Circe out. Also, using her sound/sonic-based E.V.O. abilities on so many E.V.O.s at once is exhausting.
Circe is serious and has a dry wit. For a long time, she had strongly believed that it was ultimately impossible for E.V.O.s and normal humans to get along on the Earth. Thus, she joined The Pack, thinking that being with other E.V.O.s like herself would allow her to find a place to belong. She would do whatever it took to help E.V.O-kind no matter what the cost, even if it meant ignoring her equally true and strong romantic love feelings for Rex, with difficulty. While in Hong Kong, China, with Tuck, Skwydd and Cricket, Circe appeared to be much calmer and having real fun and freedom for once. She was often seen with a smile on her face, and seemed to enjoy sitting next to or having playful hand-to-hand combat training with Skwydd. She was also seen with a much more positive and optimistic attitude, as she was no longer miserable and has found the place where she really belonged.
In "Assault on Abysus", Circe showed up at White Knight's base, informing White Knight's group that Black Knight has captured Tuck, Skwydd, and Cricket. Circe leads Rex to Abysus where the second Meta Nanite is yet to be found. When Abysus is attacked by Black Knight's men, Circe and Biowulf end up buying Rex some time to get away with the Meta Nanite. Before she sacrificed herself for his sake, she had tearfully confessed to Rex that she was never ever just using him in the past, but because she always truly loved him all along and always would. She then romantically kissed Rex and pushed him out of the aircraft, becoming captured and collared by Black Knight's men, allowing him to escape. She smiled down at him, tears welling up in her eyes, and promised that she would be okay. A Black Pawn then placed a white mind-control collar around her neck.
In "Mind Games," a shape-shifting E.V.O. named Jon Scarecrow was disguised as Circe in order to infiltrate The Plant. When the deception was eventually discovered, he used Circe's appearance to toy with Rex's emotions and break his spirit, aware of his strong feelings for her. At Providence headquarters, it was revealed that the real Circe is collared inside of a prison cell with her mouth gagged by a gray muzzle. The commotion outside had caught her attention and she stepped forward indignantly to see what was going on.
In Endgame, Part 2 she and Rex shared a close and loving hug; happy to be together. Putting her arms around him, she jokingly commented on putting himself out of a job.

Rex's Old Gang

This is an E.V.O. street gang that live in Hong Kong, China. It was revealed that Rex was the leader of this gang in his early teenage years before he lost his memory and joined Providence.
Rex found them when he and Six were sent to Hong Kong to stop a bank robbery done by them and they recognized Rex. Unfortunately, they got away, and Rex goes after them, he meets Tuck and they soon rejoice of their meet. They tell Rex that he was their leader and many other things which he didn't know. Soon, they tell him the reason behind their thievery, an E.V.O. named Quarry. It is revealed that Rex had sold them to Quarry in order for them to do his bidding. Rex, tries to convince them that it doesn't matter anymore, but they find it hard to believe and leave with Quarry. Rex goes back and battles Quarry to set them free. Eventually, Rex wins the battle and Quarry is taken by Providence.

Tuck

Tuck is a mummy-like E.V.O.
His personality is very similar to Rex's. He does not seem bothered by Rex's blackouts, treating them as normal. He also seems to have a sense of humor, trying to scare Rex when he meets up with him and joking that Rex better not forget them. Tuck can also be very cautious. This is shown when he warns Rex about getting on Quarry's bad side. Tuck can also be violent once pushed to the edge. This is shown when he punches Rex in the face after learning that Rex sold him, Skwydd, and Cricket to Quarry although Rex was supposed to be his best friend.
As an E.V.O., he is made out of bandage-like filaments that can unravel, disperse, elongate and reshape him at will, but he has never been seen. He seems to have notable acrobatic skills as seen when dodging bullets and having extreme evasive skill while fighting one on one with Six.

Skwydd

Skwydd is a humanoid squid E.V.O.
Skwydd is seen to be pretty much of the serious type, giving Rex serious/obvious answers when Rex jokes around. Skwydd is shown to be rather moody and rarely smiles, something Rex jokes about. Skwydd has an interest in entertaining people as a freak show act.
As an E.V.O., he can do many things. He can use his arms' rough skin as a shield and block bullets. He can also use them as a primary source for using blunt force on opponents. He can shoot an ink-like mist made of nanites out of his mouth for cover to escape. This ink can take a 3-D form in the air but is not actually solid. Once, Skwydd's nanite power was boosted with some kind of nanite enhancer and was able to make his ink into a solid state and use it defensively by allowing them to form into tentacles and restrain opponents, but it faded eventually. This suggests he does have the potential to make his ink solid but doesn't know how to do it. He is also shown stretching his arms to attack from a distance, and he can use this ability to cut through solid objects. In the episode "Endgame, Part 2" after he is cured it is revealed that his real name is Walter.

Cricket

Cricket, as her name states, is a Cricket-like E.V.O.
Cricket actually seems to be very friendly and outgoing, though tends to be somewhat shy around Rex due to her crush on him. She is very devoted to her friends and will not hold back when fighting to protect one, as displayed in the episode "Rabble" where she helped Rex who was pinned down by one of Quarry's Enforcers, putting her own life at risk in the process.
As an E.V.O., she developed insect-like abilities such as superhuman agility and massive leg strength. Her mutation is most noticeable in her legs, which are bent due to them being structured slightly like a cricket's or grasshopper's. With these legs, she has the ability to jump impressively high and fast and land violently on her opponents, pinning them to the ground.
Cricket returns in "Remote Control", when Quarry takes control of her. Rex mentions that she has a huge romantic crush on him, meaning it is obvious that she really does, as she is often seen flipping her short light magenta-colored hair, and flirting with him in a number of episodes.

Other characters

Ben Tennyson

Ben Tennyson is a teenager who wields the Ultimatrix, formerly the Omnitrix. He arrived in Rex's world through a space-time rift. Ben is a legend in his universe due to his use of the powerful Omnitrix/Ultimatrix. He found the Omnitrix when he was ten years of age, a watch filled with alien DNA which had fallen from space. He, his friend, Kevin, and cousin, Gwen, are part of a group called the Plumbers. When Ben first arrived in Rex's universe, they both got into a brawl as Ben mistook Rex for an alien while Rex mistook him for an E.V.O. Ben was eventually captured by the Providence Defect Group, but he escaped, trying to find a way back home. Once he finally realized that there was no way back he gave up and decided to assist Rex in his time of need. At this point, Ben met Caesar, who had come to save them both from Alpha, a dangerous creation made by Caesar six years ago during the Nanite Project.
After Alpha turned hostile, Ben used Cannonbolt to escape with Rex from Alpha. The two went back to The Plant where they played basketball and explained their origins. However, Alpha attacked the E.V.O. containment to absorb the nanites from the present E.V.O.s, including Rex. Ben helped save Rex from Alpha, causing him to flee.

Humungousaur

Humungousaur is a Vaxasaurian, a large brown alien that possesses incredible strength and dinosaur-like features. He can also grow up to a certain extent in size, with an additional increase in strength.

Diamondhead

Diamondhead is a Petrosapien, an alien that has crystalline features and can grow crystals at will. He is also able to reshape his limbs, such as turning his arm into a sharp blade, as well as firing sharp crystals as projectiles at his opponents. Additionally, he is capable of using his crystals defensively, such as creating crystal walls to protect himself and his allies.

Lodestar

Lodestar is a Biosovortian, an alien with a floating metal head in between two sharp shoulders that act as a magnetic field. He has crab-like claws and his body is mainly black with yellow feet, hands, shoulders and chest. He possesses the power to control magnetic forces, moving metals and other magnetic objects of all different types.

Rath

Rath is an Appoplexian, a humanoid alien that is similar to a bipedal tiger. He can retract two short blades from behind his knuckles that allow his punches to be more effective. Rath, like all other Appoplexians, is known for his arrogance and aggressiveness.

Big Chill

Big Chill is a Necrofriggian, a humanoid, moth-like alien whose wings and antenna can fold up into a hooded robe. He has a black body with blue and white spots, resembling ice chunks, on his limbs. He is capable of exhaling a freezing vapor that can encase his targets in a thick layer of ice. Big Chill can also render himself intangible. He can combine these abilities to freeze objects he passes through.

Cannonbolt

Cannonbolt is an Arburian Pelarota, a round alien that can curl into a ball. He can accelerate himself in this state, allowing him to burst off very quickly at his opponents. He has a yellow "shell" which enables him to defend himself. His body is mostly colored white with black stripes.

XLR8

XLR8 is a Kineceleran from the planet Kinet, and one of Ben's fastest aliens. He has a black body with a blue striped tail, and a spiked helmet with a blue visor. He has wheels on his feet, and leaves a track of black and blue lines when he runs.

Four Arms

Four Arms is a Tetramand, a four-armed, red-skinned alien with four eyes. He wears gold gauntlets on his arms and wears long black pants with a gold belt. He wears the Ultimatrix symbol on his chest.

Shocksquatch

Shocksquatch is a Gimlinopithecus from the planet Pattersonea. He is an alien with a yeti-like appearance who can manipulate and emit electric currents from his mouth. He was unlocked during the battle with Alpha in the Bug Jar.

Upgrade

Upgrade is a Galvanic Mechamorph, a humanoid alien that has black skin with green mechanical prints throughout his body. He possesses the ability to manipulate and enhance technology.

Upchuck

Upchuck is a Gourmand, a reptilian-like being who can digest, and then expel, energy and solid matter. Ben used him to carry the Alpha Nanite's compressed sphere into the Null Void.

Gwen Tennyson

At some point in Gwen Tennyson's life, she teamed up with Ben, Kevin, and her grandfather, becoming a plumber. Gwen accompanied Ben and Kevin to Japan, where Ben would make a commercial for Mr. Smoothie. When she met Rex, she seemed to be impressed by what Ben had told her about his abilities. Later, Gwen opened a portal to Rex's universe for Rex and Bobo to return home.
Gwen is able to control a pink energy called mana, also known as life energy. She can use this energy to shoot attacks, create powerful force fields, and open portals to other dimensions.

Max Tennyson

Max Tennyson is the paternal grandfather of Ben and Gwen. Despite his age, Max has shown on multiple occasions to be a formidable fighter. He was once in the United States Army, an astronaut program, and was a plumber. Before Ben got the Omnitrix, Max tried to keep the Plumbers and the aliens a secret from his family because he wanted to protect them and he did not want this life for his family; however, his plan failed when the Omnitrix and Vilgax came to Earth.

Kevin Levin

Kevin Levin and Gwen accompanied Ben to Japan for advertising in Mr. Smoothie. Later he had a discussion with Rex when Rex thought Gwen was Ben's girlfriend. However, Gwen and Ben are cousins. Gwen is Kevin's girlfriend, and Kevin becomes jealous when Rex briefly flirts with her.
Kevin is able to absorb the properties of solid matter due to his Osmosian heritage. He is able to adapt any solid matter to his body and make it an "armor" that protects him and enhances his strength. In addition, he is capable of transforming his hands into any weapon with the absorbed material.

Beverly Holiday

Beverly Holiday is Dr. Holiday's younger sister, she turned into a spider-like E.V.O. when she was thirteen. She is kept in "The Hold", a containment area meant to hold the most dangerous creatures of the Petting Zoo, and Dr. Holiday has been trying to find a cure ever since.
In "A Family Holiday", she played a major role in the episode, where Dr. Holiday, hearing word of a scientist named Dr. Branden Moses having developed a possible "cure" for incurable E.V.O.s, takes a leave of absence from Providence and takes Beverly with her, in an attempt to develop a cure with Doctor Moses. It is revealed that Moses is instead planning to supercharge the incurable E.V.O.s mutations and auction off the army of E.V.O.s to any warlord with cash. Dr. Moses successfully supercharges Beverly's mutation, transforming her into an even more spider-like form. Under threat from Six, Moses explains that the supercharging machine can be used to reverse the mutations instead and explains how to do so. With Six, Rex and Dr. Holiday's help, she is finally cured at the cost of the machine.

Peter Meechum

Peter Meechum is a man who was turned into a zombie-like E.V.O. in which while his human body was exposed, a blob-shaped head is on top of him with his actual head in the other head's mouth. In this form, he had the ability to turn anyone he touches that have nanites in them into zombie-like creatures that obey his every command. He resisted Rex's curing abilities because Van Kleiss had his daughter Sarah and forced Peter to work for him. After his daughter was rescued, Rex disarmed the bomb and cured Peter. In "Mind Games," it was revealed that Peter Meechum was one of the original Nanite Project scientists. Peter had been living in a safe house called Pandora's Box ever since he was cured. Black Knight's men managed to locate Pandora's Box and brought him to safety. While the real Meechum was sent to Providence, John Scarecrow assumed his appearance and went with Rex's team. Caesar Salazar gave Peter Meechum a tour of the Petting Zoo. When Peter asked about where White Knight is, Black Knight appeared telling her side of what happened to Black Knight. Peter recognized Black Knight as an associate of the Consortium and told Caesar that he never trusted her. Caesar continued to give Peter a tour of Providence HQ where he tells Peter that he has been recruited to restart the Nanite project. Caesar even brings Peter to where Van Kleiss was being held. In "Target: Consortium," Peter was shown to be working on the Nanite Project. Caesar brought in a yellow tube which actually contains the residue of Dr. Gabriel Rylander.

Gabriel Rylander

Dr. Gabriel Rylander is a scientist who worked on the Nanite Project with Rex's parents and other scientists. Rylander, one of the original Nanite Project scientists, wanted to change the Earth with the nanites, ending starvation and disease. After an accident, he took part in Rex's nanite treatment. Apparently, he was a good friend of Rex's family, because he is the one who was naming him. He also cared enough about Rex to try anything to save Rex's life, such as injecting the Omega-1 Nanite into Rex and pushing Van Kleiss into a reactor, despite falling into the reactor himself.
After the philanthropists who commissioned the Nanite Project stopped funding, Rylander sent each of them a "gift" – a small device which he had created to shoot a small dosage of active nanites, designed to wear off quickly. It was to show them what they had started, and not finished.
In "Dark Passage", Rylander seemed to know a lot about Rex, including the fact that he had given him his name. Rylander seemed to regret what had happened during the Nanite Event, and in doing so, injected Rex with the Omega-1 Nanite which he called "everything". He and Van Kleiss seemed to know a lot about Rex's past, although both of them never really revealed it to him - other than Rylander, who revealed the fact that Rex had an older brother. Before he could tell Rex more about his past, Van Kleiss attacked, gravely injuring Rylander. Before Van Kleiss could finish Rex off, Dr. Rylander woke up and pushed himself and Van Kleiss into the reactor, presumably killing them both.
In "Black and White", Dr. Gabriel Rylander's residual energy was found by Providence and placed in a special yellow tube. In "Target: Consortium," Caesar is still trying to find a way to restore Gabriel Rylander. Caesar uses a cart to bring the yellow tube containing Gabriel's residue into the lab where Peter Meechum and Van Kleiss are working in. Caesar states that Gabriel didn't die and that his body was split on a molecular level. When Rex finds the Jungle Cat E.V.O. threatening Van Kleiss in the lab, the residue of Gabriel Rylander ends up forming into a ghost-like state where he is glad that he can see Rex again.
In "Endgame, Part 1", Gabriel Rylander is among those who protest against Black Knight's idea to have the Master-Control Nanite torn out of Rex. When Rex is hooked up to the Cylcatron, Gabriel and Peter have a disagreement with Caesar about continuing on with the plan. In "Endgame, Part 2" Gabriel and Peter tell the Consortium that controlling the vastly limitless cosmic God-like powers of the Meta Nanites would prove to be a problem. After Rex does a mass-E.V.O. curing throughout the planet, Gabriel Rylander and Peter Meechum agree with Caesar to work on a different project.
Rylander is a passionate scientist who believes so much the potential success of the Nanite Project. Driven by his guilt, he left his family and life to complete the Nanite Project alone. And he seems to be vengeful. For example, he sent the device to give warnings to the people who refused funding him.

Claire Bowman

Claire Bowman is a girl that Noah likes. Claire is best friends with a clumsy girl name Annie. In "Operation: Wingman", Claire agrees to go to the prom with Noah only if he can find Annie a date. Noah asks Rex to be his wingman. Despite several setbacks, Claire and Annie enjoy their prom night with Noah and Rex. Claire returns in the episode "Haunted" where she and Annie spend a night with Rex and Noah in a haunted house where a ghost cat-like E.V.O. was lurking. Noah and Claire become closer in this episode. When in an elevator in the house, the E.V.O. slams into the doors and crushes them shut, thus locking Noah and Claire inside. Inside, Claire admits to Noah that she is claustrophobic, and so he comforts her and keeps her calm. At the end of the episode, Claire expresses her appreciation for what Noah did for her and afterward they almost kiss but are interrupted when Caesar arrives.

Annie

Annie is a girl who is best friends with Claire. Annie is a notorious jinx as she is extremely clumsy and as a result, she can't find a date for the prom in "Operation: Wingman". When Claire was asked out by Noah, she told him she would go with him on the condition that he could find Annie a date. Noah picked Rex as he was unaware of Annie's reputation and because Rex was the only person capable of surviving a date with her. Shockingly, Annie's clumsiness proves to be an asset when Rex uses it to blow the rabbit E.V.O. up with a heat-seeking missile. After the prom, the girls agree this is the best date they have ever had, but Rex states that despite Annie being nice and cute, he'll never go on a date with her again. However, in "Haunted", Noah once again convinces Rex to go on a date with her, so he can go with Claire.

Kenwyn Jones

Kenwyn Jones is a former Providence cadet.
Providence was responsible for saving her family. Kenwyn later joined it because she wanted to repay her debt to them. The experience seemed to have a profound effect on her, causing her to take her training very seriously.
Kenwyn is a serious, focused and hardworking Providence agent. She was top of her class which also shows that she has impressive intelligence. After Rex joined her team, he brought her grades down, causing her to descend from being number one. Out of anger, she tried to sabotage Rex, showing she can be vengeful at times. Kenwyn is also shown to be very uptight and controlling. On her first Providence mission with Rex, it was clearly evident that she thought she knew more.
She is shown to be very agile and skilled with firearms and Providence weaponry. Being human, she has great hand-to-hand combat and gymnast skills, and has great physical strength and flexibility. Taking the gun for herself, she put good use to it. Kenwyn's intelligence seems to be quite impressive as well. She excelled in the academic goals of Providence Basic Training and was ranked #1 out of all the other students. She even graduated top of the academy as a lieutenant.
Rex and Kenwyn are both Providence teammates and are very good friends and their platonic relationship with each other has changed dramatically from where they first started. When Kenwyn first met Rex, she disliked him because of the way he presented himself and how he made her grades drop from being number one in her class. She tried to get revenge on him by turning off the collars, used to prevent the E.V.O's from using their powers in training. Strangely things became mixed up, and she was sent to go training instead. After E.V.O's began to escape from the Cage, Kenwyn saved Rex by acting as a distraction. She later admitted the truth to Rex and apologized.
In "Lost Weekend," Kenwyn returns to assist Rex and Bobo at an E.V.O. party in the desert. She is now a full-fledged Providence agent and lieutenant.

The Six

The Six are a group of mercenaries that consists of the six most dangerous people on the Earth. Each member's name goes by how dangerous they are. As noted by Six, the ranking focuses on how dangerous they are which in turn is determined by skill level and personality.
Six was once a member of this group before joining Providence. The Six first appeared in the episode "Divide by Six" shown to have ambushed Rex.
They attacked Rex to test his skills. Along with Agent Six, the group kidnapped Rex for the purpose of curing One, who has been transformed into an E.V.O. Rex, on the other hand agrees to do it, but the thing is that the group wants to kill him in order to put an end to his misery. When something goes wrong, it turns out he is incurable. All them except Six and Rex then voted to kill him but Six and Rex fought to prevent it from happening. They battled until One possessed Rex and used him to contact Six mysteriously and disappeared by causing the whole mountain top to be filled with a valley of grass.

One

One was the most dangerous man on the planet and the leader.
He was one of the first people to go E.V.O. after The Nanite Event, but he was strong-willed enough to suppress the vicious instincts that awoke within him through meditation. To protect his students and innocent people from his new destructive side, One ordered a cell built for himself in center of a volcano on a remote island. The cell contained a safety protocol; if he failed to enter the safety code every 41 minutes, the whole room would collapse into a volcano, killing everyone inside. When Rex tried to cure One for the second time, One possessed Rex's body for a short time to bid farewell to his students. When Six said that he was going to take One home, One replied that he was already home, suggesting that he was with all the people in the world that he cared about. After his death, One bonded with the island and restored its natural balance, becoming one with everything.
Out of all of One's students, Six was shown as being the closest to him. Unlike the rest of the Six, Six was willing to sacrifice his mentor's "freedom" in exchange for the possible cure. One was proud of Six's choice of joining Providence and becoming a hero, even if that meant fewer meetings between them.

Dos

Dos is an elderly Spanish gentleman, and is the second most dangerous man on the planet.
Due to being the second most dangerous man on the planet, his fighting skills are very proficient and he has remarkably quick reflexes. His main weapon is a cane that can be used as a laser pistol, a gas emitter, or sharpened into a blade.
Dos and the rest of The Six kidnapped Rex for the purpose of curing One. When Rex failed to cure him, he and the others agreed to kill him because they believed that killing him was better than locking him up in a cage. After Dos was defeated, he helped Rex even though One died eventually.
As the second most dangerous man on the planet, Dos is the cruelest of his group and never shows mercy. Though he cares for his mentor, One, he is very willing to kill him, just to "put him out of his misery".

Trey

Trey is a large man with a cajun accent, who is physically the strongest of The Six.
Trey is not the most intelligent among The Six, he acts like a stereotypical hillbilly-thug. He is shown to be cruel like the rest of the Six and has a habit of cracking bad jokes, which constantly annoys Five. He is slightly less insulting than Dos and IV, but he was not above cracking a cruel joke that Rex's cries sounded like his dogs when Rex was struggling to cure One. He also has a habit of smiling most of the time, which differs from the other members of the Six, who usually keep a neutral look most of the time. Like the other members of the Six, he is very secretive about his life and job. He may work as an enforcer, due to Six's comment about him "breaking arms and legs".
In "Six Minus Six", Trey, along with Five, encountered Six on the same mission. When they spotted Rex, he and Five reminded Six that no witness was allowed. Trey tried to remember the contract's description, yet eventually failed. At first, they worked together to eliminate Rex, but soon affected by Rex's taunting words they were against each other. He and Five retreated once they were defeated by Six.

IV

IV is a mummy-like mercenary, because he has bandages covering his body, that he uses as a weapon, it seems he is able to control them. He can use them to bind opponents and can even use them to his very own aid.
He has a rough voice and lost his pinky during a case in Malaysia, which is the only case they lost, and blames Six for that. Out of all the six, he is the most paranoid and would quickly assume the worst.

Five

Five a is a pink-haired Cockney accented English rocker girl as shown by her unique sense of fashion and guitar.
Five appears to have a short temper, as she openly expresses her annoyance every time Trey says something completely unrelated to the situation or unintelligent. Similar to her number, she is colder and crueler then Six, but she is shown to be slightly kinder than the ones ranked above her. Unlike Dos and IV, she never once insulted Rex on the mission to save One, and she even threatened Trey for making a cruel joke towards Rex when he was trying to cure One. However, she was still not above attacking Rex and Six, and trying to kill her old master. Like the others members of the Six, she is very secretive about her life and her job.
Her main weapon is an electric guitar which she uses as a blunt instrument. With it, she's able to send strong seismic waves by smashing her guitar onto the ground, allowing it to go along a trail to attack her opponent. Five wields the instrument with impeccable skill, which when combined with her speed and fighting abilities makes it a formidable weapon. It also seems to be very durable, as she is able to bludgeon her opponents without causing any damage to the guitar, deflect sword slashes, and absorb the impact of Trey's fists.
She later returns in "Six Minus Six" when both she and Trey appeared with Six when they encountered each other on the same mission. When they spotted Rex, she and Trey reminded Six that no witnesses were allowed. At first they worked together to eliminate Rex, but were soon affected by Rex's words and fought against each other. Five and Trey retreated once they were defeated by Six.

Fitzy Feakins

Fitzy Feakins is a human E.V.O., who is urgently wanted by Providence because of his E.V.O. powers. He is currently hiding out from Providence and is an ally of the Providence Defect Group. According to Feakins, prior to his E.V.O. transformation, he was just an ordinary, rock-loving accountant. After being pulled over and interrogated by Providence, Rex and Noah had run into them. Rex and Noah rescued him and decided to escape with Feakins. They soon found out his powers, the ability to interfere with active nanites around him, and communicated with Dr. Holiday, who informed them that it was obvious that Black Knight wanted him only to make E.V.O. capture much simpler, specifically with Rex himself. After a long and difficult pursuit, they all met up with Holiday at a planned rendezvous. They stationed him in an ice cream truck to hide away from Providence. Rex called it the perfect hiding place due to Feakins' love of milkshakes. Unluckily, Feakins was captured by Providence, saying that he feared being killed by Black Knight. He was forced to neutralize Rex's nanites, allowing him to easily be defeated and taken in by Providence.