Raaif

The Raaif (Taxonomically Ira idolona; dubbed Wraiths by Humans) were an aggressive race of near-reptilians, who roamed the outer regions of the Milky Way Galaxy. They were believed to be a Tier 3 race by the Interstellar Union.

Biology and physiology
The Raaif were amongst the few sentient non-humanoids. It has been recorded that they were of a semi-aquatic near-reptilian family, that would natural spend much of their lives submerged under fridged pools of liquid nitrogen on their homeworld. They would only leave these pools on hunts, as their desire for cold temperatures urged them to remain submerged unless the atmospheric temperature was within their ideal temperature range, which it wasn't on their planet. Even so, they were capable of surviving on land indefinitely, as their starship were extremely cold to reduce the need for their bathing in nitrogen.