Tiamat

In Babylonian mythology, Tiamat is a chaos monster, a primordial goddess of the ocean, mating with Abzû (the god of fresh water) to produce younger gods. It is suggested that there are two parts to the Tiamat mythos, the first in which Tiamat is 'creatrix', through a "Sacred marriage" between salt and fresh water, peacefully creating the cosmos through successive generations. In the second "Chaoskampf" Tiamat is considered the monstrous embodiment of primordial chaos. Although there are no early precedents for it, some sources identify her with images of a sea serpent or dragon. In the Enûma Elish, the Babylonian epic of creation, she gives birth to the first generation of deities; she later makes war upon them and is killed by the storm-god Marduk. The heavens and the earth are formed from her divided body.

Tiamat was known as Thalattē (as a variant of thalassa, the Greek word for "sea") in the Hellenistic Babylonian Berossus' first volume of universal history. It is thought that the name of Tiamat was dropped in secondary translations of the original religious texts because some Akkadian copyists of Enûma Elish substituted the ordinary word for "sea" for Tiamat, since the two names had become essentially the same, due to association.