Cocky racer in a fable (4)
I believe the answer is:
hare
'cocky racer in a fable' is the definition.
(I've seen this in another clue)
This is the entire clue.
(Other definitions for hare that I've seen before include "Leveret" , "Game, -- and hounds" , "Swift mammal" , "may be electric!" , "Rabbit-like creature" .)