Hyena was a species of carnivore mammal native to the continent of Africa. A group of these were included in Sunnydale Zoo. Dr. Weirick, a closeted Primal, had them quarantined so he could perform a ritual and transfer their spirits into his body. Unfortunately, Sunnydale High students Kyle DuFours, Heidi Barrie, Rhonda Kelley and Tor Hauer violated quarantine while bullying fellow student, Lance Lincoln. They were frightening Lance, by forcing him close to the hyenas' pit, when Xander Harris came to Lance's rescue. Unbeknowst to them, the ritual was completed; the hyenas' spirits transferring into the bullies and Xander.
Buffy Summers, with the aid of Rupert Giles, Willow Rosenberg and Weirick made plans to dispossess the students. The protagonists were unaware Weirick actually wanted the hyenas' spirits and abilities for himself. Weirick completed the predatory act, against Willow, and transferred the spirits into his body. Immediately, Buffy fought him; causing the possessed man to fall into the hyenas' pit and be devoured by the real hyenas.
In their initial state, or while possessing human beings, hyenas like fresh, raw meat-- whether from animals or humans. For this reason, they were turned off by cooked meat.