Trolls are huge humanoid monsters, as witlessly stupid as they are bone-crushingly powerful. They commonly join marauding Greenskin armies. Trolls are found in greatest numbers in the Troll Country and other Chaos-saturated regions near the Chaos Wastes. Trolls are by nature creatures of Chaos, the corrupting effects of Chaos playing a primary role in their origins. It was once believed Trolls and Ogres were related creatures, and that Trolls were in essence a further degeneration of the Ogre race.
Trolls are voracious creatures, mostly motivated by food and eating, and appropriately, their digestive systems can cope with almost anything, including, it is rumoured, rock and metal. Trolls are infamous for several abilities. Their digestive juices are among the most corrosive acids known in the Old World, and disembowelling a Troll can often result in the death of the attacker himself as the acid sprays out. Secondly, Trolls possess an uncanny ability of quickly regenerating even the most grievous wounds. In due time almost all wounds will be healed, the only known weakness being fire.
Trolls sometimes make use of weapons, although they are more than capable of ripping someone apart with their bare hands and claws.
Besides the bog standard common troll, there are a number of distinct breeds:
- River Trolls live in the vicinity of water; rivers, lakes, or swamps being a common choice. They are scaly and particularly slimy fellows. 
- Stone Trolls are native to mountainous and rocky areas, and occasionally eat rocks and stones. As a result they have acquired stone-like characteristics, like very hard skin. Another extraordinary characteristic is that they are extremely resistant towards magic.
- Chaos Trolls - While all Trolls are inherently creature of Chaos, some have undergone more direct mutation that has twisted them into even more fearsome creatures than normal. They can possess all forms of mutations, two heads being a common affliction. Like all Trolls, they are a terrifyingly powerful, fast moving creature with flesh that can quickly restore itself, or, to be precise, warp itself into ever more terrible mutations. Unlike them, however, they literally use vomit as a weapon, acidic bile dissolving the flesh of their puny enemies. They can throw up even more repulsive things, including swathes of carnivorous worms or even the energy of Chaos. While common, river and stone trolls ally with Greenskins, these children of Chaos are loyal to their Dark God fathers and they will often accompany the Warriors of Chaos in their campaigns. Unfortunately for the latter, no amount of mutations has managed to cure their stupidity and cowardice.
- 1: Warhammer Armies: Orcs & Goblins (7th Edition), pg. 21
- 2: Warhammer Armies: Beasts of Chaos (7th Edition), pg. 31
- 3: Games Workshop Official Site