Bemused with creature (3)
I believe the answer is:
emu
'creature' is the definition.
(emu is a kind of creature)
'bemused with' is the wordplay.
'with' says the answer is hidden in the clue.
'EMU' is hidden in the letters of 'bemused'.
(Other definitions for emu that I've seen before include "Australian running bird." , "Aussie runner" , "unit of measurement" , "Australian non-flyer" , "Parky's nemesis" .)