Five-toed pachyderm (8)
I believe the answer is:
elephant
'five-toed pachyderm' is the definition.
(I've seen this before)
This is the entire clue.
(Other definitions for elephant that I've seen before include "Then leap (anag.)" , "Five-toed pachyderm" , "Large animal (in the room?)" , "Trumpeting animal" , "I'll never forget" .)