Tiamat

Tiamat is the draconic goddess of greed and pride, revered among chromatic dragons as the Dragon Queen. When mortals dare to whisper as to the form of the Dragon Queen, they say that she appears as a titanic dragon with five heads, each one a different color.

The Chromatic Dragon is supremely avaricious, representing the most wicked tendencies of dragonkind. Her pride is such that the bare existence of mortals is a slight against her--and Tiamat never forgives or forgets a slight. In the Dragon Queen's mind, the universe rightfully belongs to dragons; and one day, dragons will claim what is rightfully theirs, annihilating the mortals who dared to keep treasure away from a dragon's hoard.

For this reason, Tiamat's worshippers are almost exclusively chromatic dragons. Some misguided mortalfolk do worship the Dragon Queen, but they are generally understood to be delusional or desperate.

It is said that Tiamat is the sister of the draconic god Bahamut. In addition, worshipers of Vaelor claim that the Prince of the Nine Hells has Tiamat captive as one of his prized prisoners--a claim that invokes the ire of any chromatic dragon who overhears such a blasphemy.