Drop litter and stuff (3)
I believe the answer is:
pig
I believe this clue is a double definition.
'drop litter' is the first definition.
('pig' can mean to give birth to a litter of pigs)
'stuff' is the second definition.
(both can mean to eat lots of food)
'and' acts as a link.
(Other definitions for pig that I've seen before include "Quantity of metal" , "Greedy eater" , "Eat ravenously" , "Unforged metal" , "Eat greedily" .)