Troll (The Lord of the Rings)

The Cave Trolls were a subspecies of troll in the Lord of the Rings series by J.R.R. Tolkien. They had thick skin, which could not be pierced even by Elvish blades. They were rather dimwitted and would turn to stone if exposed to sunlight. They were usually used by Goblins and Orcs as beasts of burden and heavy weapons in their wars for Sauron. Due to their vulnerability to sunlight and inherent lack of intelligence, Sauron later replaced Cave Trolls for the Olog-Hai, or Troll Folk; as the Olog-hai had no such weaknesses. Cave Trolls were famously used by the goblins against the Fellowship of the Ring at the Battle of the Chamber of Mazarbul.