The Tandu are a fictional extraterrestrial species from David Brin's Uplift Universe. Physically they are a spindly insectoid species. They despise death, injury and any form of weakness. If forced to humiliate itself by conversing with a member of an alien species as an equal, a Tandu will cut off one or two of its own legs as a form of ritual purification. A Tandu who has been deemed by his superiors to have failed unforgivably is expected to commit "suicide" by cutting off his own head.
Worship
Like many Uplift Universe species, the Tandu worship the Progenitors and would by human standards be considered religious zealots. They are a highly xenophobic species, viewing all other intelligent lifeforms simply as enemies or tools for them to use. They follow the "Inheritor" sect of the cult of the Progenitors, believing that upon the return of the Progenitors the current power structure of galactic civilization will be destroyed and the universe will be cleansed of "unworthy" races. The Tandu believe they will be given the privilege of being made the Progenitors' holy warriors, who will slaughter the unworthy upon their return.
Clients
The Tandu have created at least two slave races that are powerful psychic adepts: Episiarchs and Acceptors. The Tandu may have violated the rules of the uplift institute by making them truly dependent on them. The Tandu have had records of their clients sealed.
Episiarchs
Episiarchs are shaggy quadrupeds that have the ability to temporarily alter reality by force of will, and are used to open short-lived portals that allow Tandu ships to travel instantly to distant parts of the universe, giving them nearly unmatched strategic speed. This method of travel is not popular among other starfaring races because of the risk involved, as it randomly results in the destruction of entire ships or even fleets. The Episiarchs have other military uses as well, although these are not greatly elaborated upon. In Startide Rising an Episiarch is used to create a temporary dry pathway on waterlogged land so that a party of Tandu infantry may move more easily.
Acceptors
Acceptors are spider-like creatures that have the ability to psionically "see" the universe around them in great detail and clarity, that is, they "accept" data at a quantum level at great range. They are used by the Tandu as living sensors.
Incrementors
Incrementors have only appeared in the book Contacting Aliens: An Illustrated Guide To David Brin's Uplift Universe and may be later changed. Incrementors were the Tandu's first Client race, their being listed last in formal introductions likely indicates a demotion in status. They resemble multi-legged dandelions with sensory nodules circling below a globe of soft fuzz. They are likely Psi-adepts like the rest of the Tandu client races. How they serve the Tandu is unknown.
Technology and relationship with Earthclan
In the novel Startide Rising, a Tandu warship used a probability engine, directed by an Episiarch, to leap into the middle of an enemy formation. The ship created a great deal of destruction, before the Tandu ship ceased to have ever existed. The risks of this probability drive deter most non Tandu races from using such technology. The Tandu have fought several minor skirmishes with the Earth Confederation. They are described as being extremely dangerous enemies, often winning even when the numerical odds favored the humans. This may not necessarily say all that much about their prowess, as humans in this universe are an extremely weak race, but more advanced alien species seem to respect their abilities. The Tandu are organized as a raiding force and use mostly Battlecruiser-like ships with great speed and firepower but poor protection that rely mostly on not getting hit for their survival. A Tandu light destroyer was described as being equipped with "antimatter beams", possibly antiparticle beams or possibly more exotic antimatter/matter conversion weapons.
