In Babylonian mythology, Tiamat is the primordial sea being defeated by Marduk.
Tiamat appears in the Enūma Eliš, the Babylonian creation epic preserved in tablets from the second millennium BCE. She represents the saltwater sea and joins with Apsu, the freshwater deep, to produce the first generation of gods. After conflict erupts among the deities, Tiamat becomes the opponent of the younger gods and creates a monstrous army.
Marduk, the storm god and son of Ea, agrees to fight Tiamat if the gods recognize him as their supreme ruler. Armed with winds, a net, a bow, and a spear, he traps and kills her. Marduk then splits her body and uses its parts to organize the cosmos, including the heavens and the earth. The story therefore explains both creation and Babylon’s claim to divine supremacy.
Calling Tiamat a sea serpent or dragon is traditional, but the ancient text gives her both human and animal features, and modern scholars debate how precisely she should be classified. She is more securely understood as a primordial sea goddess or cosmic ocean. Apep and Leviathan belong to Egyptian and biblical traditions, respectively.