A little beast (3)
I believe the answer is:
cub
'a little beast' is the definition.
(I know that cub is a type of offspring)
This is all the clue.
(Other definitions for cub that I've seen before include "Young lion or fox" , "'Baby animal, fox say (3)'" , "Young newspaper reporter" , "Baby animal, bear say" , "A baby fox or bear" .)