Pilots are large crustacean-like creatures that have four arms on their upper half and a lower half adapted to bond with a Leviathan spacecraft. They have a very rich and complex language that is too advanced for translator microbes to interpret unless spoken in very simple form. One sentence in this language can communicate the same amount of information as dozens of sentences in other languages.
The primary distinction of Pilots is their ability to bond with Leviathan spacecraft. When bonded, they do so for life, and die with their Leviathan; they can no longer exist independently for more than an hour or so. Leviathans can live about 300 cycles (slightly longer than 300 Earth years).
Pilots are chosen for bonding from among the population by their Elders, and are carefully screened for maturity and ability. The bonding process itself takes several cycles to complete naturally, although there are methods to artificially accelerate it. However, some of these methods cause severe pain for the pilot over the entire length of time it is bonded to the Leviathan.
Pilots choose to bond because it is their only means of space travel, though further details on this limitation are not given. Pilots staying on their home planet can live up to 1,000 cycles (slightly more than 1,000 Earth years), so bonding with a Leviathan causes them to lose a significant amount of their lifespan. They are willing to make this sacrifice in order to travel the galaxy.
Pilots possess the ability to multitask, necessary for their simultaneous handling of the many systems aboard a Leviathan required by its passengers. The Leviathan's vital systems, however, are not affected by the absence of a Pilot. Pilots also have the ability to regenerate severed arms. The process takes at least several solar days, though exactly how long is unclear.
Much of what is known about them comes from the Pilot of the Leviathan Moya, known only as Pilot. It is indicated that all bonded members of the Pilot race become known only as "Pilot". Any other naming conventions held by them are unknown.