Little creature nearly run over (3)
I believe the answer is:
elf
'little creature' is the definition.
(I've seen this in another clue)
'nearly run over' is the wordplay.
'nearly' means to remove the last letter.
'run' becomes 'flee' (to flee is to run away).
'over' says the letters should be written in reverse.
'flee' with its last letter taken off is 'fle'.
'fle' written backwards gives 'ELF'.
(Other definitions for elf that I've seen before include "A leprechaun" , "A small sprite with magic powers" , "Mischief-maker" , "1 ac fairy" , "Imp-like being" .)