Mark of Chaos - Symbol used by the Chaos Space Marines in the year 40,000 Edit
The followers of chaos fall into 5 category, and are made up almost exclusively of Humans with an Elder God to represent each faction. Each god strives for dominance over the others, but their power comes from both their knowing and unknowing followers.
Their willing followers either worship all four gods, or one in specific. Followers of Chaos who worship no god are the Undivided. They receive few if any benefits from the gods, but few if any punishments. A follower of a single god may benefit of their god, but may also be cursed or punished by the others.