Wild animals (6)
(Other definitions for hyenas that I've seen before include "Nocturnal carnivouous mammals of Asia and Africa" , "Dog-like animal of Africa" , "Dog-like animals with cry like human laughter" , "Dog-like animals that sound as if they laugh" , "Dog-like nocturnal carrion feeders" .)
'wild animals' is the definition.
(I've seen this in another clue)
This is the entire clue.
(Other definitions for beasts that I've seen before include "Basset found among other animals" , "Brutes" , "Creatures; basset (anag.)" , "Basest sort of animals" , "Fine animals" .)