Creature which may be part hen (7)
I believe the answer is:
panther
'creature' is the definition.
(thesaurus)
'may be part hen' is the wordplay.
'may be' indicates an anagram.
'part'+'hen'='parthen'
'parthen' anagrammed gives 'PANTHER'.
'which' is the link.
(Other definitions for panther that I've seen before include "Big cat" , "See 2" , "Then rap the large black cat" , "Black leopard" , "kind of feline" .)