Fabled slacker (4)
I believe the answer is:
hare
'fabled slacker' is the definition.
(I've seen this in another clue)
This is all the clue.
(Other definitions for hare that I've seen before include "Timid creature" , "who often got stiff?" , "Long-eared mammal" , "animal running in fields" , "may be electric!" .)