Bemused with creatures (4)
I believe the answer is:
emus
'creatures' is the definition.
(emu is a kind of creature)
'bemused with' is the wordplay.
'with' indicates the answer is hidden within the clue.
'EMUS' can be found hidden inside 'bemused'.
(Other definitions for emus that I've seen before include "Running birds" , "Fast, but not high-fliers" , "Large flightless birds of Australia" , "Largest native Australian birds" , "laboratory units" .)