Rampant GI shot flier (9)
I believe the answer is:
ptarmigan
'flier' is the definition.
(ptarmigan is a kind of birdanimal)
'rampant gi shot' is the wordplay.
'shot' indicates anagramming the letters.
'rampant'+'gi'='rampantgi'
'rampantgi' with letters rearranged gives 'PTARMIGAN'.
(Other definitions for ptarmigan that I've seen before include "Northern game bird - map rating (anag)" , "Arctic grouse" , "Type of mountain grouse" , "Grouse - giant pram (anag)" , "Grouse-like bird" .)