Fine, a hog without tail is an animal! (5)
I believe the answer is:
okapi
'an animal' is the definition.
(I've seen this before)
'fine a hog without tail' is the wordplay.
'fine' becomes 'ok' (synonyms).
'hog' becomes 'pig' (synonyms).
'without tail' means to remove the last letter.
'pig' with its final letter taken away is 'pi'.
'ok'+'a'+'pi'='OKAPI'
'is' is the link.
(Other definitions for okapi that I've seen before include "Animal of central Africa" , "African ruminant" , "African leaves fancier" , "Ruminant related to the giraffe" , "African animal like giraffe with shorter neck and striped body" .)