The Bzzit Khaht as it appeared on screen
The Bzzit Khaht were a sentient species, whose homeworld was a member of the United Federation of Planets by the late 23rd century.
In 2286, a Bzzit Khaht councilor attended a Federation Council trial of James T. Kirk. (Star Trek IV: The Voyage Home)
A Bzzit Khaht
The name of this species comes from FASA's Star Trek IV Sourcebook Update. While strictly a non-canon source, it is the only widely recognized source for names of most of the Star Trek IV aliens.
According to this source, the Bzzit Khaht's homeworld is known as Althos IV (β).