Olog-hai were "strong, agile, fierce, and cunning" trolls created by Sauron, not unlike the Uruk-hai, and
were able to withstand sunlight while under the sway of Sauron's will. They seldom spoke and were said to know no language other than the Black Speech, in which Olog-hai means "troll-folk" (singular Olog "troll"). Because of their cunning, they were thought by some to be giant Orcs, rather than trolls. They appeared towards the end of the Third Age and could be found near Dol Guldur and in the mountains around Mordor.[5] In the Battle of the Morannon, there appear "hill-trolls" of Gorgoroth which are implied to be Olog-hai in one of the Appendices to The Lord of the Rings (the term is not used within the story proper). These were described as being taller and wider than men, and their hide or armour was described as a mesh of horny scales. They had black blood. Peregrin Took slew the leader of these trolls at the Battle of the Morannon; and after the destruction of the One Ring and the fall of Sauron, the surviving trolls scattered as if mindless.[6]