The Deep Ones are creatures in the Cthulhu Mythos of H. P. Lovecraft. The beings first appeared in Lovecraft's novella The Shadow Over Innsmouth, but were already hinted at in the early short story "Dagon". The Deep Ones are a race of intelligent ocean-dwelling creatures, approximately human-shaped but with a fishy appearance. They regularly mate with humans along the coast, creating societies of hybrids. Numerous Mythos elements are associated with the Deep Ones, including the legendary town of Innsmouth, the undersea city of Y'ha-nthlei, the Esoteric Order of Dagon, and the beings known as Father Dagon and Mother Hydra. After their debut in Lovecraft's tale, the sea-dwelling creatures resurfaced in the works of other authors, especially August Derleth.
Summary
Lovecraft provides a description of the Deep Ones in The Shadow Over Innsmouth: Lovecraft describes the Deep Ones as a race of undersea-dwelling humanoids whose preferred habitat is deep in the ocean. However, despite being primarily marine creatures, they can come to the surface and can survive on land for extended periods of time. All Deep Ones are immortal; none die except by accident or violence, and they can grow to massive size. They are said to serve the beings known as Father Dagon and Mother Hydra, as well as Cthulhu. They are opposed by mysterious beings known as the Old Gods, whose powerful magic can keep them in check. This detail is one of the vestigial hints that August Derleth developed as the mostly unnamed Elder Gods.
Deep One hybrid
The backstory of The Shadow over Innsmouth involves a bargain between Deep Ones and humans, in which the aquatic species provides plentiful fishing and gold in the form of strangely formed jewelry. In return, the land-dwellers give human sacrifices and a promise of "mixing"—the mating of humans with Deep Ones. Although the Deep One hybrid offspring are born with the appearance of a normal human being, the individual will eventually transform into a Deep One, gaining immortality—by default—only when the transformation is complete. The transformation usually occurs when the individual reaches middle age. As the hybrid gets older, he or she begins to acquire the so-called "Innsmouth Look" as he or she takes on more and more attributes of the Deep One race: the ears shrink, the eyes bulge and become unblinking, the head narrows and gradually goes bald, the skin becomes as it changes into scales, and the neck develops folds which later become gills. When the hybrid becomes too obviously non-human, it is hidden away from outsiders. Eventually, however, the hybrid will be compelled to slip into the seato live with the Deep Ones in one of their undersea cities.
Father Dagon and Mother Hydra
Mother Hydra and her consort Father Dagon are both Deep Ones overgrown after millennia ruling over their lesser brethren. Together with Cthulhu, they form the triad of gods worshipped by the Deep Ones. Mother Hydra is not to be confused with the entity in Henry Kuttner's story "Hydra".
Y'ha-nthlei
"Cyclopean and many-columned Y'ha-nthlei" is the only Deep One city named by Lovecraft. It is described as a great undersea metropolis below Devil's Reef just off the coast of Massachusetts, near the town of Innsmouth. Its exact age is not known, but one resident is said to have lived there for 80,000 years. In Lovecraft's story, the U.S. government torpedoed Devil's Reef, and Y'ha-nthlei was presumed destroyed, although the ending of the story implies it survived. The name Y'ha-nthlei may have been inspired by the Lord Dunsany character "Yoharneth-Lahai", "the god of little dreams and fancies" who "sendeth little dreams out of PEGANA to please the people of Earth." Other authors have invented Deep One cities in other parts of the ocean, including Ahu-Y'hloa near Cornwall and G'll-Hoo, near the volcanic island of Surtsey off the coast of Iceland. Anders Fager has described the city of "Ya' Dich-Gho" as located in the Stockholm skerries. It is accidentally destroyed in 1982 during a Swedish submarine-hunt. At least two surviving Deep Ones live in Stockholm. One of them sells aquarist's supplies. The destruction of Ya' Dich-Gho is described in "When Death Came to Bod Reef"; the city's history in "Herr Goering's Artefact" and the life of the survivors in "Three Weeks of Bliss".
