Troll
A troll is a mythical beast of Norse mythology. In the modern fantasy scenario, trolls fit within the medieval mythos, and are usually regarded as racially related to orcs and goblins (and sometimes giants too). Trolls are usually described as large and green, virtually indestructible and eat virtually anything. They are, however, slow moving, although they are powerful. In the Lord of the Rings novels, which is loosely based on Norse mythology, trolls were described to die when exposed to direct sunlight, when they would turn to stone.
Trolls are grumpy and live under bridges. They are very territorial and will deny use of the bridge to strangers or require the fulfilment of special conditions.
As with spam, troll also has a different meaning on the internet. On the internet, a troll is a person who deliberately starts fights, who goads others into getting angry, with the aim to see the person who they troll get banned, or else to embarrass themselves somehow. Like the mythical troll, the internet troll is virtually indestructible, as they have many lies to tell about why they are starting fights, claiming innocence. Even when the site owner finally wises up to it, the troll keeps coming back.
Trolls are most common on newsgroups and other message boards, but also exist on wikis, journals and other text mediums. Whilst their effect on gaming is minimal, they do exist in online games as well. Indeed, the comic strip PvP had a troll named Skull who at one point was described as being "a troll from Ultima Online" (meaning the internet troll type, not the mythical game type, although it was meant to mean both). Eventually, however, PvP changed Skull's biography such that he is now a mythical creature that is sent to earth to help children believe in mythical creatures.