Takhisis

Supreme goddess of evil in the Dragonlance setting, Takhisis is incredibly ruthless, powerful, ambitious and cunning, but so much of a treacherous douchebag that she tends to ruin her own plans.

Patron goddess of the Chromatic Dragons and creator of the Draconians, her most famous form is a massive five-headed dragon. As this has led more than one gamer to speculate that she may just be an avatar (or bastardization) of Tiamat, most authors tend to focus on her humanoid incarnations, the seductive 'Dark Temptress' and a fierce warrior-woman.