Huge creature that's hunted bird (6)
I believe the answer is:
osprey
'bird' is the definition.
(osprey is a kind of bird)
'huge creature that's hunted' is the wordplay.
'huge' becomes 'os' (abbreviation for outsize).
'creature that's hunted' becomes 'prey'.
'os'+'prey'='OSPREY'
(Other definitions for osprey that I've seen before include "Bird of fine feather" , "Large bird preying on fish in inland waters" , "Marine bird of prey" , "predatory bird" , "A feather trimming (6)" .)