Bemused with creature (3)
I believe the answer is:
emu
'creature' is the definition.
(emu is a kind of animal)
'bemused with' is the wordplay.
'with' indicates the answer is hidden within the clue.
'EMU' is hidden within '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" .)