The Rise of Tiamat
Tiamat (pronounced tee-a-maht, also known as the Nemesis of the Gods, is the queen of evil dragons Tiamat is also the eternal rival of her brother Bahamut, ruler of the good metallic dragons.
Tiamat 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.
Tales tell of avatars of Tiamat that can appear as a dark-skinned lady, or as a dracolich.
Tiamat dwells at the gate of Dis, the diabolical city that is the second layer of Hell.