Foe of Frodo (3)
I believe the answer is:
orc
'foe of frodo' is the definition.
(I've seen this in another clue)
This is the entire clue.
(Other definitions for orc that I've seen before include "Tolkienian monster" , "Fairytale monster" , "Fierce goblin" , "Tolkien ogre" , "Tolkienian creature" .)