Tiamat (Dungeons & Dragons)

In the Dungeons & Dragons role-playing game, Tiamat is a powerful draconic goddess, usually depicted as a European dragon with multiple heads. The name is taken from a goddess of the same name from ancient Mesopotamian mythology which is substantially different (and did not have multiple heads). See the article on Tiamat for more information.

Tiamat is a queen of evil dragons and a member of the default pantheon of D&D gods.

Like most other draconic deities, she is the offspring of the dragon creator deity Io. She is the eternal rival of her brother Bahamut, the ruler of the good metallic dragons. She dwells in Avernus, the first layer of the Outer Plane of Baator (also known as the Nine Hells). The first edition of Advanced Dungeons & Dragons named her as the ruler of Avernus; later editions reserved the rulership of the layers of Baator for powerful baatezu (devils).

In many campaign settings, the draconic pantheon of gods consists of the leader Io, as well as Aasterinian, Bahamut, Chronepsis, Faluzure, and Tiamat. Other draconic gods may be present in different campaign settings.

Description
In most Dungeons & Dragons campaign settings, Tiamat is the five-headed queen of the evil chromatic dragons. She has one head for each primary color of chromatic dragon (black, blue, green, red, white), and each head has the powers of a member of the respective race of dragonkind.

Tiamat in various campaign settings
It should be noted that in Dungeons & Dragons, despite the apparent notable differences between the mythological Tiamat and even her various campaign setting incarnations, it was the original intention of Gary Gygax, Ed Greenwood and others, as well as the basis for some of the ideas for the Planescape setting, that the various Tiamat incarnations, as well as other deities with real-world equivalents, were ultimately aspects of a single entity that happened to be active on more than one plane of existence.

Dragonlance
In the Dragonlance campaign setting, Tiamat's counterpart is Takhisis, the Dark Queen. Though some believe them to be the same being, others feel that there are enough differences to classify the two as separate entities.

Forgotten Realms
In the Forgotten Realms campaign setting, all of the above holds true, except where contradicted by Realms canon. Tiamat is one of the few surviving gods of the Untheric pantheon (based on the Sumerian mythology), having battled Marduk in ages past, and also a member of the draconic pantheon, daughter of Io, the slayer of Gilgeam the God-king of Unther, Nemesis of the Gods.

Tiamat in other games and media
Various monsters called Tiamat, patterned after the Dungeons & Dragons character, have appeared in other fantasy games, particularly computer and console role-playing games. A five-headed dragon, intended by Takhisis herself to become her physical incarnation, has to be fought near the end of the game Dark Queen of Krynn.

In the Dungeons & Dragons TV series, Tiamat is the arch enemy of the "main" villain, Venger.