Trolls

Trolls are a hulking humanoid creature with low intelligence.  They congregate in small gangs, and often fight over territorial disputes between other gangs.  Trolls are a carnivorous creature, preferring to eat anything smaller than them, with a preference towards many humanoid creatures, but especially humans.
Trolls have an incredible regenerative property, and are durable as a result.  However, their bloated bodies are also very flammable and proves to be a tremendous weakness.  They also have several variations, depending on age and geographical location.  Mountain trolls tend to have tougher hides from rubbing against stone and essentially scaling themselves with the rocks that wedge themselves into their bodies, which then heal with the stone shards trapped within.  Forest trolls adorn themselves in bark and, despite their lumbering stature, can still be somewhat elusive.  Colossal Trolls are among the most dangerous, signified by their tremendous size and age.