Hill-trolls
From Tolkien Gateway
A variety of troll adapted for life among hills and moorland. Aragorn's grandfather Arador was slain by them in the hills north of Rivendell, and a company of these creatures were among the armies that Sauron loosed from the Morannon in the War of the Ring.
In appearance they were man-like, but larger, and seem to have been covered with hard scales. They were fearsome and vicious, bellowing like beasts as they stormed into battle, and beating their enemies down with great hammers.
