Hydran

Hydrans were a non-humanoid species. Their government was the Hydran Kingdom. (Star Fleet Battles, : "Humans, Romulans and Space-Beasts")

Biology
Hydrans were notable to breathe methane, which could be uncomfortable or lethal for most Federation species. They had three arms, legs and eyes, as well as a tough, leathery skin. They had three sexes: male, female and matriarchal, only two of which are sentient. All births resulted in multiples of 3 (at least one of each sex) who are taken care of by the Matriarchals.

Culture
Males tended to dominate command-level positions, as well as science and engineering, while females tend to form up most of the worker classes, as well as marines and fighter pilots. Some females could hold command positions, or even the throne. Matriarchals were non-sentient and were homemakers.

Their culture was deeply religious and their religion bordered on animism, as each household, starship, squadron and fleet possessed a god or a set of gods. Some gods were of a higher order, but what gods were put in the public limelight were decided by what groups came to power.