Animal caught by shotgun, gracelessly falling over (3)
I believe the answer is:
gnu
'animal' is the definition.
(type of antelope)
'caught by shotgun gracelessly falling over' is the wordplay.
'caught by' says the answer is hidden in the clue.
'falling over' is a reversal indicator (letters falling back).
'ung' can be found hidden inside 'shotgun gracelessly'.
'ung' backwards is 'GNU'.
(Other definitions for gnu that I've seen before include "Large African antelope" , "Gun to get antelope" , "Strange gun for an antelope" , "Literally wild beast" , "animals" .)