Tc'a

T'ca are yellow, leathery, and snakelike in appearance. They have multiple eyes (and brains!) and are part of the six-species Compact.

Tc'a speech sounds like layered multitonal wails; single-brained species (like humans) almost always need technological assistance to communicate, and even then, messages read out as a seven-part matrix that can be interpreted in any direction. Another Compact member-species, the oxy-breathing stsho, appear to be able to communicate more directly.

T'ca are the most interactive of the Compact's methane breathers, and almost exclusively handle methane-side operations at Meetpoint Station, the physical center (and trade zone) of the Compact. Tc'a are the only ones able to communicate meaningfully (if there is such a concept) with the mysterious knnn.

Biology and Reproduction
T'ca have some sort of symbiotic relationship with one of the Compact's other methane-breathing species, the spiderlike Chi, whose homeworld lies within t'ca space. What exactly this relationship entails in unknown.

T'ca fission off a small, new, t'ca when placed under extreme stress. This has been observed in a moment when a t'ca's life was in danger, it is unknown what level of stress or danger is needed to trigger this reaction.

Behind the scenes
They are part of the Chanur series of books by CJ Cherryh, and appear in all five novels (The Pride of Chanur, Chanur's Venture, The Kif Strike Back, Chanur Homecoming, and Chanur's Legacy). While ostensibly part of her larger Alliance/Union series, they have not made any appearances in those stories.