Two-footed animals (6)
I believe the answer is:
bipeds
'two-footed animals' is the definition.
(I've seen this in another clue)
This is the entire clue.
(Other definitions for bipeds that I've seen before include "Two-legged animals" , "Humans, say" , "Upright creatures" , "Two-footed animals" , "Animals that walk on two feet" .)