The Knnn are a methane-breathing race that inhabits a part of space in The Compact, from the Chanur books by C.J. Cherryh. Although oxy-breathers cannot easily communicate with them, they co-exist with the oxygen-side inhabitants of the Compact, sometimes even on the same stations. They speak to their oxy neigbors through an interpreter race, the tc'a, also of the methane side. The Knnn are said to resemble 'snarls of black hair with legs,' whereas the tc'a are recognizably serpentine (thanks to khym_chanur for a correction).

Knnn motives, methods, likes, dislikes (and in fact much of anything about their species) remain a complete mystery. They have apparently been made to understand by the tc'a that simply swooping in, picking up an oxygen-breather's cargo or, in some cases, the oxy-breather themselves and then swooping off again is frowned upon in the oxygen-dwelling side as piracy. However, this progress simply means that usually they leave a random item in trade when they do so.

The Knnn have jumpships which are far more capable than those piloted by oxygen breathers. They can actually turn in hyperspace, or navigate, and can maneuver in realspace at G levels that would crush the oxys in moments. No-one knows how they do this, and their ships look like conglomerates of random components. This has caused many folk on the Oxy side of the line to lose sleep.

Their call is a weird, ululating song, and most respectable hani traders get quite nervous when the knnn show interest in their doings.