Animal, leopard perhaps, consuming duck on island (5)
I believe the answer is:
coati
'animal' is the definition.
(I've seen this before)
'leopard perhaps consuming duck on island' is the wordplay.
'leopard perhaps' becomes 'cat' (leopard is a kind of cat).
'consuming' means one lot of letters goes inside another.
'duck' becomes 'o'.
'on' means one lot of letters go next to another.
'island' becomes 'i'.
'cat' enclosing 'o' is 'coat'.
'coat'+'i'='COATI'
(Other definitions for coati that I've seen before include "Raccoon relative" , "carnivore from South America" , "American denizen" , "South American animal" , "Flesh-eating mammal" .)