The Cave-trolls are a type of troll that live in dark caverns and caves.They are unintelligent and ill-tempered. Since they have poor eye sight, they uses their nose to find prey. Some cave trolls live in Moria. This particular troll attacked the fellowship of the ring. Legolas killed the troll with his bow after a fight with the rest of the fellowship, although in the book such a battle never occured.