Creature putting leg under twice (5)
I believe the answer is:
'creature' is the definition.
(I've seen this before)
'leg under twice' is the wordplay.
'leg' becomes 'on' (cricket term, fielding positions).
'under' is a charade indicator (letters next to each other).
'twice' becomes 'bis' (I've seen this in other clues).
'on' after 'bis' is 'BISON'.
'putting' acts as a link.
(Other definitions for bison that I've seen before include "US wild ox", "Kind of shaggy cattle", "Large humped bovid of N America", "Buffalo Bill's prey", "Wild cow".)