Father also included creature (5)
I believe the answer is:
panda
'creature' is the definition.
(panda is a type of creature)
'father also included' is the wordplay.
'father' becomes 'pa' (pa is a kind of father).
'also' becomes 'and' (I've seen this before).
'included' is an insertion indicator.
'pa' placed around 'and' is 'PANDA'.
(Other definitions for panda that I've seen before include "WWF symbol" , "(a cuddly-looking bear)" , "Chinese native" , "Raccoon-like animal" , "Black-eyed animal" .)