🐙 Tiamat is an eldritch draconic entity in the fictional universe of the Dungeons & Dragons pencil-and-paper roleplaying game by Wizards of the Coast. A version of her also appeared in the Dungeons & Dragons cartoon. If Tiamat from Dungeons & Dragons had to be somehow fitted into the Mythos, she is powerful enough to be a Great Old One, but understandable enough to be an Elder God. In strict terms since she is a character from Sumerian mythology she is really a God of Earth.
Tiamat (aka, The Dragon Queen, Nemesis of the Gods, The Undying Queen, The Queen of Chaos, The Avaricious, and The Bane of Bahamut) is a draconic abomination who is the queen of the evil Chromatic dragons and a goddess of greed & vengeance, whose form is that of a five-headed dragon. Her ultimate goal is to conquer all the realms. She boasts monstrous strength, expansive wings which grant her flight, a scorpion-like tail complete with poisonous stinger, the ability to open inter-dimensional portals, immunity or resistance to most attacks due to her natural armour and massive size, and the ability to cast magical spells. Her five heads possess the breath attacks of the five chromatic dragon species; lightning, fire, acid, ice, and poison gas.
Tiamat was a member of the Draconic pantheon and after the destruction of their plane by the Spellplague joined the Faerûnian pantheon. Tiamat is the sister and eternal rival of the draconic entity Bahamut, the ruler of the good metallic dragons. She is a vain, spiteful, greedy, hateful, and arrogant being who focuses on acquiring ever more power and wealth, and never forgives any slight. Tiamat can be charming and fey when needed, but sooner or later her true nature comes out. She disdains mortals, seeing them only as disposable tools. Insatiably greedy for material wealth, she prefers that her worshipers bring her treasure as gifts, rather than gathering it for herself. Tiamat has had many draconic consorts, enjoying male company and having children with them, whom grew up to become her mortal agents. It is believed that she lusts after her brother Bahamut.