Klaha

The Klaha (also known as Denebians) were a sentient species from Deneb V. They are known to themselves as the Klaha, but gained the common designation of "Denebian" because they were the first race from the Deneb system encountered by Earth. (TOS novel: My Enemy, My Ally)

A pair of Denebian ensigns served on the USS Aldebaran (Nebula class) in 2376. As their natural environment consisted of a type of heated slime, the Denebians required specialised environmental suits while working in a standard class M environment. Both perished when that ship was destroyed by a surprise attack by the Jem'Hadar. (DS9 novel: Avatar)