Troll of Nadroj

Mountain Trolls (Orcus Troglodytarium Nadrojium) are a species of troll semi-sapient humanoids.

Physical Description
The Trolls of Nadroj stand taller than Mountain Trolls, whom they generally resemble, with the exception of longer, more pointed ears, and, most notably, grossly oversized clawed hands.

Behaviour
Like Mountain Trolls, Trolls of Nadroj are only debatably sapient, but were often used by Dark Wizards as minions in their armies, as they seem predisposed to obey powerful wizards (a remnant, no doubt, of their creator Alexander Nadroj's training).

Magical Abilities
Trolls have no active magical abilities. However, latent magic makes their skin highly spell-resistant, and presumably strengthens their arms so that their large hands do not pull them down. A Nadrojian Troll's claws can be crushed to a fine powder and used in various strength-increasing potions, although it is liable to make the cauldron explode if not stirred properly.

Habitat
Trolls of Nadroj are nigh extinct in the wild. However, unscrupulous Russian goblins are suspected to breed them for profit and sell them to Dark Wizards for a high price.

14th Century
In the 14th century, the Dark Wizard Alexander Nadroj captured Mountain Trolls and tried to warp them using magic into useful soldiers for his armies. His experiments resulted in the birth of a new subspecies of trolls, the Trolls of Nadroj. After Nadroj's defeat, his Trolls were slated to all be destroyed as dangerous Dark experiments. However, some of Nadroj's allies smuggled a few Trolls of Nadroj out of the country, presumably selling them to the ancestors of the very goblins who are now illegally breeding them in Russia.

20th Century
Presumably through the aforementioned Goblin smugglers, Lord Voldemort acquired three Trolls of Nadroj whom he used in 1976 in the First Wizarding War. Alastor Moody, however, was able to bring down two of them after a fierce battle, and the last one was accidentally killed by Voldemort himself in a fit of rage.

British Ministry of Magic Classification
Owing to their status as magically-engineered Dark Wizard minions, the dangerous Trolls of Nadroj are classified as Beasts with the threat level of XXXX.

Canon

 * Troll of Nadroj on the Harry Potter Wiki