Wyrm (World of Darkness)
The Wyrm is the evil god and ultimate villain in the game known as Werewolf: The Apocalypse, from White Wolf Game Studio.
In this game, werewolves, or Garou, are heroes, protecting the Earth's environment from the depradations of a heedless humanity. According to the cosmology of the story, the universe began with the Triat: the Wyld, the personification of chaos; the Weaver, the embodiment of order; and the Wyrm, the force of entropy. For awhile, the three existed harmoniously, with the Wyrm quietly undoing what the other two created, but something went wrong and the Wyrm (and some say the other two as well) went mad and began devouring too much too fast, in an attempt to destroy the entire universe.
The Garou, as part human (Weaver-influenced) and part wolf (Wyld-influenced), instinctively understand that the universe is in need of balancing, and the minions of the Wyrm (the Pentex corporation, bane spirits, vampires, Malfeans, Black Spiral Dancers, etc.) are in their way.
The Wyrm is frequently depicted as a snake as large as the planet with multiple heads; these heads representing the Urge Wyrms, each of which is a minor god in its own right. There is also a little overlap with Judeo-Christian mythology; the Wyrm is sometimes identified with both the serpent in the garden of eden and the dragon in the Book of Revelation of John.