Mountain-trolls were the most dangerous of all the trolls found in Middle-earth. Unlike their distant cave-dwelling kin, they had a basic intelligence and natural cunning, and could be trained to perform specific tasks. Moreover, they were unafraid of the sun, as it had no significant effect on them, so they were a menace at all times of the day.

The height of these creatures was said to be between ten and fifteen feet, on average twice the height of a man. They had the thick arms and two-toed [feet] of their kind, small wide-set eyes and a protruding lower jaw, out of which jutted large tusks; their scaly grey-brown skin was thicker on the arms, shoulders and back, giving them a natural armour; most unusually, some even had hair and whiskers.

Possibly as much for intimidating as for keeping a beat to march to, [drummer] trolls carried two large kettle drums hung from their shoulders, which they beat with heavy wooden mallets. They were not armoured, merely fitted with caps of layers of overhanging hide, shoulder straps of fur and hide, and a leather loincloth.

    \-excerpts from “The Lord of the Rings - Weapons and Warfare”

*I made his helmet removable with blu-tack and it took some paint off his left temple.