Wild gorilla snatching at reptile (9)
I believe the answer is:
alligator
'reptile' is the definition.
(alligator is a kind of reptile)
'wild gorilla snatching at' is the wordplay.
'wild' indicates an anagram.
'snatching' indicates putting letters inside.
'gorilla' anagrammed gives 'alligor'.
'alligor' placed around 'at' is 'ALLIGATOR'.
(Other definitions for alligator that I've seen before include "one bites voraciously?" , "predator" , "From fearsome beast" , "Reptile like a crocodile" , "River creature" .)