Tiamat is the queen and mother of evil dragons. She is a greedy, vain, and arrogant goddess who embodies all the strengths of her chromatic progeny but few of their weaknesses. Tiamat holds a vicious hatred of Bahamut, the God-King of Dragons, and all that he stands for. She embodies the ideal of supremacy, and therefore believes that the weak of the world are deserving of eradication, finding that only those who fight and dominate in order to survive as worthy of such a privilege. She is entirely focused on the acquisition of personal power and wealth and views mortals as hapless pawns in her struggles with other deities.
Tiamat can be charming when necessary, but her self-serving, evil, reptilian nature is readily apparent to those who look. She enjoys the company of male dragons, and has many great wyrm consorts of the chromatic varieties. She has an insatiable greed for treasures, but prefers that her followers bring it to her in the form of gifts instead of searching for riches on her own.
For a time, Tiamat was a reluctant servant of the greater gods Bane and later Asmodeus. Tiamat is also the eternal rival of her brother Bahamut, ruler of the good metallic dragons. Before entering the Faerûnian pantheon, she was a member of the Draconic pantheon, and for some time she was also a member of the Untheric pantheon. She is the patron of the ancient Flan kingdom of Caerdiralor.
Most chromatic dragons worship and acknowledge Tiamat's sovereignty (blue and green dragons obey her most readily). About 95% of them serve their goddess in some way. Those who prefer a different deity have a grim fate waiting for them: in the depths of her lair behind a pair of 100' adamantine doors Tiamat has a collection of the souls of those chromatics sworn to other deities, locked up for eternity. Naturally, the grotesque reptilian creatures known as the Spawn of Tiamat (see below) worship her as their mother.
Aside from the chromatics dragons and spawn, Tiamat counts a notable number of humanoids amongst her servants, mainly Dragonborn and other part-dragons, such as spellscales, dragon-kin and half-dragons, and some humans. Most kobolds worship individual dragons as gods, but the smarter ones who know about Tiamat might turn a tribe to her worship instead. Kobolds may also revere her as their progenitor.
The Queen of Chromatic Dragons demands reverence, homage, supplication, and tribute from her subjects. As a divine dragon, her hoard is believed to be worth trillions.
Clerics of Tiamat are primarily occupied by the twin tasks of acquiring an ever-increasing hoard of wealth for the faith and sabotaging the faiths of other deities. As a result, they occupy most of their waking hours with an unending series of thefts, assassinations, acts of vandalism, and arson. In Unther and Chessenta they are primarily concerned with seizing as much power as possible, while in western Faerûn, the cult's agents are focused on infiltrating and subverting the Cult of the Dragon.
The clergy within the temple are often training acolytes mercilessly, before subjecting them to battles against one another, to the death, in the name of their god. It is not uncommon for these acolytes to even kill their masters before fleeing the temple, unleashing this same evil upon the world. More generally speaking, however, Tiamat prefers to hand-pick those who come into her service, usually by sending them visions of her demands and instructing them to either accomplish great feats in her name, or to attend the temple, and succeed her trials.
VestmentsThe ceremony garb of a humanoid priest of Tiamat is a form-fitting suit of scales. Dragons or those whose scales naturally cover their bodies don't require this, of course. Adventuring garb typically includes scale mail.
HierarchyAlthough she claims dominance over all evil dragons (and despite her misleading title, Queen of Chaos), Tiamat's priests, who are known as Wyrmlairds or Wyrmkeepers, are either neutral evil or lawful evil. Tiamat's church is regimented by a strict hierarchy of ranks and titles, beginning with the lowly Custodians of the Copper Chalice and continuing with, in ascending rank, the Defenders of the Silver Shield, Wardens of the Electrum Mail, Guardians of the Gold Scepter, Keepers of the Platinum Crown, Scales of the White Wyrm, Horns of the Black Beast, Wings of the Green Gargantua, Talons of the Blue Baatoran, Breaths of the Red Ravager, and the Dark Scaly Ones leading them all. Many clerics multiclass as fighters, sorcerers.
TemplesTemples to Tiamat are often built within the lairs of long-dead dragons. They are filled with piles of wealth to be sacrificed to the Chromatic Dragon, as well as traps to keep out heretics and the unfaithful. Few dragons keep shrines to her in their own lairs, because they don't wish the goddess to know exactly how much treasure they have, for fear she will demand a greater cut of it.
RitualsEvil dragons celebrate great victories by torturing prisoners and committing other atrocities in Tiamat's name. Prayers to the Dragon Queen focus on the promise of filling the world with evil dragons and either destroying it or dominating it utterly.
Clerics of Tiamat pray for their spells at dusk, in hopes she will return the sun the following morning, as part of a ritual known as Tithing. The Tithing requires an offering of a small amount of treasure to the goddess; the tithe is cupped in the priest's hands or talons, and when a prayer is completed, the valuables sometimes (10% of the time) simply vanished.
Tiamat's clergy also perform numerous other daily ceremonies in homage to their mistress. The Rite of Respect is a complicated ritual of abasement and appeasement which is performed by non-dragons. It must be performed while approaching any spawn of the Dragon Queen. This ceremony does not provide any ritualistic protection from the dragon's fury, but failure to perform the ceremony with rigorous perfection is sure to draw the great reptile's ire.
In Unther, the Dark Scaly Ones have proclaimed the day of the first full moon after Midsummer a holy day dedicated to the Dark lady. Known as the Festival of Vengeance, this day marks the defeat of Gilgeam by Tiamat, Nemesis of the Gods. In Unthalass the day is marked by general anarchy, rioting, and widespread mayhem incited by the clergy and the faithful and is punctuated by the consummation of long-simmering acts of revenge. During this time, the clerics of the Mulhorandi and Faerûnian pantheons seek to contain the looting and destruction, but prominent officials must beware of the numerous assassination attempts executed by Tiamatis worshipers.
OrdersThe Cult of the Dragon, also known as Keepers of the Secret Hoard or Wearers of Purple, is trying to break the Goddess out of her divine imprisonment and allowing her to roam the realm again. A faction of the cult encourages evil dragons to become dracoliches. Their belief is that dracoliches are destined to one day rule Faerûn and beyond. This faction acts as an information network for their draconian "masters" and bring gems and riches as offerings.
The Spawn of TiamatTiamat has recently begun to create the Spawn of Tiamat in notable numbers, who are born from the eggs of dragons instead of the regular wyrmlings, or from two Spawn of the same kind mating. Dragons who sire the Spawn of Tiamat consider it a good omen and a sign of Tiamat's favor to have part-dragon monsters born instead of their own children born from their eggs. These are divided into five groups, based on their color: the Blackspawn who consist of strong raiders (and one type looking like spiders for some reason), the Bluespawn who are mostly unintelligent beasts of war, the Greenspawn who are small(ish) ambushers who work best in forest and swamp environments, the Redspawn who are the Spawn's primary source of magic (fire magic of course), and the Whitespawn who gather in large numbers and excel at fighting in cold environments and clan warfare.
Rival deities of all creeds and from every pantheon are inherently tyrannical. They seek only power, at any cost, despite their honeyed words. The Dragon Queen is the only being powerful enough to defy the gods and overthrow their despotic rule, as demonstrated by her overthrow of the other Untheric deities. Work tirelessly toward the day when Tiamat will banish the gods from Faerûn and unite the world under her rule. Toward this goal, follow her commands unquestioningly and be willing to sacrifice yourself in her service. To overthrow the gods requires power, and power is acquired through the accumulation of wealth and magic. Power demands respect. Chromatic dragons everywhere are to be venerated as the spawn of the Dragon Queen and paid homage. When Tiamat assumes her throne, her draconic children shall serve her as dukes, and her clergy as their mortal vassals.
Tiamat is the five-headed queen of the evil chromatic dragons. She has one head for each of the most common colors of chromatic dragon (black, blue, green, red, white), and each head has the powers of a member of the respective race of dragonkind. Her underbelly and stubby legs are greenish white blending into the colors on her sides and back. Her fat, bloated body is a blending of various chromatic dragon forms with an appropriately multicolored hide, and becomes muddy brown at her tail, which is tipped with a poisionous stinger like that of a wyvern.
Tiamat has also been known to manifest as a dark-haired human sorceress.
Tiamat was one of the first deities to have aspects, or lesser avatars. These aspects may appear as powerful versions of her chromatic children or as versions of her own five-headed form.
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 draconic pantheon of gods consists of the leader Io, as well as Aasterinian, Bahamut, Chronepsis, Astilabor, Hlal, Lendys, Faluzure, Garyx, Tamara and Tiamat.
Three Dukes of Hell (granted to her by Bel) serve Tiamat and command her armies on Avernus. Malphas leads 40 companies of abishai, Amduscias leads 29 companies of abishai, and Goap leads three companies of erinyes. With Pearza of the Dark Eight, Tiamat created the first abishai.
Tiamat presently has five consorts, great wyrms of each chromatic dragon species. Previous consorts include Apsu, Kingsu, Ephelomon, the red dragon Etiol, and the now-undead dragon Dragotha. Four of Tiamat's children include An-Ur, Dhakoth the Corruptor and Mordukhavar the Reaver, and Kurtulmak. An-Ur (the Wandering Death) wanders the Ethereal Plane, devouring whole demiplanes. It supposedly sprang into being from Tiamat's first breath. Maybe she had a consort named First Breath, but An-Ur resembles no draconic species, except perhaps the ethereal moonstone dragons. Dhakoth the Corruptor was born on the Negative Energy Plane. Its father is unknown. Mordukhavar the Reaver is the offspring of Tiamat and Cantrum of the Dark Eight. Kurtulmak is also her son, at least according to some myths.
Periodically Tiamat has battles with the Babylonian god Marduk, who dwells in Arcadia. She also battles Bahamut, her lawful good counterpart. Heironeous and Moradin also consider themselves her enemies, and Stratis was an enemy of Tiamat when he was alive. Tiamat claims not to need allies, although she has many pacts with Bel and with lawful evil deities such as Hextor.
MythologyElder Brother Vorel's Death
Tiamat's enmity with Bahamut dates back to their creation, when Io made them; they were made with the intention of becoming complements and mates, but their personalities were too much at odds. Where Bahamut represents the nobility and sense of justice his father had, Tiamat represents his other characteristics: avarice, pride, arrogance, and the raw power to get away with it. Tiamat murdered Vorel, their elder sibling, and tried to frame Bahamut for the deed. Io realized who was truly to blame and banished Tiamat from his presence.
The Violation of Tiamat's Lair (Kobold Creationism)
In one kobold creation myth, Kurtulmak owes his existence to an assault launched on Tiamat by an army of thieves shortly after she had laid a clutch of eggs. Badly injured and with her lair heavily damaged, she caused one of her eggs to hatch, thus creating Kurtulmak. The newly hatched godling quickly began creating a defensive perimeter of traps and restoring the caverns. During the process, Kurtulmak found an egg of Tiamat's that had fallen away from the nest and, deeming it had been away for too long to ever hatch naturally, used his magic to cause it to hatch, thus producing miniature versions of himself: the first kobolds.
The Banishment of Tiamat
Many myths claim that Tiamat lived for a long time on the Prime Material Plane, seeding it with evil dragons and dark magic. Eventually she was banished to the Nine Hells by Bahamut and a sky/sun god (perhaps Pelor or Heironeous).