Fury's leader at the end: previously put on ass (6)
I believe the answer is:
onager
'ass' is the definition.
(type of wild ass)
'fury's leader at the end previously put' is the wordplay.
I cannot really understand how this works, but
'leader' could be 'e' (I've seen this in other clues) and 'e' is located in the answer.
'at' could be 'on' (location) and 'on' is found within the answer.
This explanation may well be incorrect...
'on' acts as a link.
(Other definitions for onager that I've seen before include "The ass might be an odd orange colour" , "Creature" , "donkey" , "Asiatic wild ass" , "Orange Asiatic ass" .)