Mount last stuffed big cat (8)
I believe the answer is:
stallion
'mount' is the definition.
(I've seen this before)
'last stuffed big cat' is the wordplay.
'stuffed' indicates an anagram.
'big cat' becomes 'lion' (lions are big cats).
'last' anagrammed gives 'stal'.
'stal'+'lion'='STALLION'
(Other definitions for stallion that I've seen before include "Stud" , "Male horse, often used for breeding" , "Male horse lost in atolls" , "Male steed" , "Mount" .)