"I am not what I am" speaker (4)
I believe the answer is:
iago
'i am not what i am speaker' is the definition.
(I've seen this in another clue)
This is all the clue.
(Other definitions for iago that I've seen before include "Othello's Ancient" , "villain in play" , "Othello's enemy" , "Othello's treacherous officer" , "stage villain" .)