Don Diego de la Vega's alter ego (5)
I believe the answer is:
zorro
'don diego de la vega's alter ego' is the definition.
(I've seen this in another clue)
This is the entire clue.
(Other definitions for zorro that I've seen before include "Doglike fox" , "Fictional hero" , "'The Mark of - - ' (film)" , "Tyrone Power & Anthony Hopkins film role" , "Hispanic Robin Hood" .)