Ancient Greek fabulist (5)
I believe the answer is:
aesop
'ancient greek fabulist' is the definition.
(I've seen this before)
This is the entire clue.
(Other definitions for aesop that I've seen before include "A pose by Greek writer of fables" , "Greek teller of animal tales with a moral" , "Poses as ancient Greek writer" , "A pose of famed fable teller" , "Greek storyteller" .)