Werewolves
Werewolves in Arda are wolves from first to last, bred from wolves and inhabited by imprisoned spirits, with the wits of a Man in a beast's frame.
The werewolves of Arda do not turn from Man to wolf, and the moon has nothing to do with them. They are wolves in shape from first to last, bred out of wolves and then given dreadful spirits, imprisoned inside those bodies by the master who made them. What that produces is the intelligence of a Man inside the frame of a great beast, which means they can be spoken with, bargained with and lied to. They served Sauron in the First Age and were still in his service in the Third. The isle of Tol Sirion held so many of them that the place was renamed for it, Tol-in-Gaurhoth, the Isle of Werewolves.
How far into The Lord of the Rings have you read?
Set your place and this page rewrites itself to exactly that point. Nothing ahead of you will show.