Also called Thalattē in Hellanistic Babylonian,
or "Ummu-Hubur who formed all things"
Tiamat is not actually known for certain to be a dragon as such. She considered a "chaos monster" or a primordial goddess of the ocean from ancient Babylonian texts. The Enûma Eliš, the Babylonian epic of creation, lists her as the mother of gods and goddesses as well as the mother of dragons and serpents. But she's not necessarily a dragon herself, though later Babylonian art depicts her as such:
She is most famous for her battle with another Babylonian god, Marduk. Marduk, the god of thunderbolts, determined to establish himself as the head of the pantheon of gods, killed Kingu, whom Tiamat had put in charge of the Tablets of Destiny. Infuriated, Tiamat, who had loved Kingu, went to battle against Marduk. And she lost.
Marduk took the dead body of Tiamat, and from her ribs, crafted heavens, turned her weeping eyes into the source of the Tigris and the Euphrates, and spread her tail across the sky to form the Milky Way:
It is interesting to note that this story of Marduk and Tiamat is not one that deals with ethics or morality. Neither Marduk nor Tiamat is considered good or bad. Though Tiamat is an agent of destruction, she is not considered wicked. As the author of British Dragons says:
"The issues involved (in the Enûma Eliš) are not ethical, but cosmic; these myths are concerned with the creative process that shaped the universe and restored order after a threat of chaos, or of grave deficiences in the natural order" (p. 24).
The story of Tiamat and Marduk has had a profound effect on dragon lore. We see it reiterated in many dragon-slayer tales, particularly the "storm god fighting the sea serpent" aspect. Tiamat, as a goddess of primordial oceans, is often depicted as a sea serpent. The tale is retold in the form of Thor (another thunder god) battling Jörmungandr (another sea serpent). Also Zeus (yet another thunder god) battling Typhon (a many-headed dragon) is similar to the tale.
So whether or not Tiamat was intended from the beginning to be a dragon, she has effected dragon mythology throughout the ages!
Sadly, that effect did make its way into cartoon world:
Oh dear, yes. She has been immortalized forever as a many-headed dragon queen pitted against six spunky teens and pre-teens in the Dungeons andDragons TV series.
("I liked that one!" my husband says. "We are no longer speaking," says I.)
Poor Tiamat. How are the mighty fallen!
Tiamat on a scale of 1-10
Evil: 0She is a dreadfully scary primordial goddess of chaos and destruction . . . but, as stated above, the old Babylonian myth is not concerned with morality, but considers its deities to be above such things. Ultimately, she is no more evil than a hurricane.
Scariness: 10Um, she's a primordial goddess of chaos and destruction! She doesn't have to be evil to be terrifying!
Poison: 1I can find no reference to her being poisonous.
Hoard: 8She possesses the Tablets of Destiny, which I think count as a pretty decent hoard, all in all.
Cleverness: 5Will give her a flat five here. I'm not going to say she isn't clever. But hurricanes aren't respected for their cleverness, and neither is she.