Larva (4)
'larva' is the definition.
(grub is a kind of larva)
This is all the clue.
(Other definitions for grub that I've seen before include "Larva; food (sl.)" , "Table needs" , "Insect larva or slang food (4)" , "Larva; dig shallowly" , "Caterpillar - food" .)
'larva' is the definition.
(caterpillar is a kind of larva)
This is all the clue.
(Other definitions for caterpillar that I've seen before include "Moth/ butterfly larva" , "Heavy tracked earth-moving vehicle" , "Track" , "looper, perhaps" , "He made do with a mushroom" .)
'larva' is the definition.
(I know that tadpole is a type of larva)
This is the entire clue.
(Other definitions for tadpole that I've seen before include "Potential frog" , "Embryonic frog" , "developed from spawn" , "Young toad" , "Little creature in water" .)