Trolls are magical beings, and are known for being greedy, yet powerful and vicious creatures.
Trolls are flatulent creatures whose views on beauty differ greatly from humans'. They have tails, clawed fingers which are larger than that of a Human, sharp teeth like big tusks, and are usually grey and pale, with furrowed skin. They also have green blood. They hate fresh food and cleanliness, preferring to eat rotten food and live in filthy conditions. They have an uncontrollable desire from riches, not unlike goblins. They are rarely seen as they hate all other forms of life.
Trolls are old allies with dragons.
One troll, with the use of a Potion supplied by her servant, Jonas, posed as the Lady Catrina to take over Camelot for its riches In fact, it did succeed at enchanting Uther to the point of marrying him and becoming Queen of Camelot (Beauty and the Beast).
Trolls have enormous strength, able to rip a door off it's hinges and throw a fully grown man across a room. Their breath can make food rot so that it suits their taste.
Trolls have strong magic, beyond most human capacity. They are able to cast powerful love spells, and when someone is under such a spell they will do anything the troll wants them to. Trolls with knowledge of the right spells/potions are able to shape shift.
Though sometimes blinded by greed, trolls are also quite clever.