Eve (Supernatural)

Eve was an ancient creature who was imprisoned in Purgatory long ago by God for an unknown purpose. She was known as the Mother of All Monsters, and was extremely ancient and powerful. All vampires, werewolves, Dragons, Leviathans, Wendigos and Kitsunes were created by her.

It is unknown of her relation to the Leviathans, yet the Leviathan possessing Edgar described her as a "whore" and unworthy of being related to the vampires. The Leviathans hated every other creature, including Eve, but due to certain similarities Eve may be a relation of theirs.

Release
In 2011, Dragons had assumed human form, thanks to Eve, and were abducting young women and holding them hostage in sewers, and this called the attention of Sam Winchester, and Dean Winchester who went into the sewers to investigate, and found the Dragons inside. Dean wounded one and killed another with a Dragon-killing sword, and the others flew off.

Later on, the other Dragons chose the sacrifice to free Eve, and bought the female sacrifice to a cliff, and recited a Latin incantation to crack open a portal to Purgatory. Once the portal was open, they threw the girl in, who ended up possessed by Eve, the Mother of All Monsters, who rose out of the pit and told her Dragons to begin a war to eradicate humans.

On Earth
On Earth, Eve set about seducing many human males, as her host was attractive. She first seduced a truck driver and told him all human religions were lies, and said it was foolish that humans were waiting for the Apocalypse when it had already come and gone and they hadn't even noticed. Eve ridiculed the driver's faith in God and Jesus and then unleashed a creature unto him, a Khan Worm, which possessed him, and made him kill his wife, for which he was arrested. This again called Sam and Dean's attention and the driver had no memory of why he had done such a thing.

Later, Eve met two young men, one of whom was attracted to her, saying that Heaven must've lost an angel. Eve stroked his face and turned him into a monster. Eve then walks into a bar. The patron says "Hey, you want a drink?" Eve then goes up and turns him into vampire so he gets his drink. Huh!

Sam and Dean tracked Eve down to the bar where she was chilling, having posed as a waitress, and were attacked and subdued by her monsters. Eve was so strong the angel Castiel lost his powers. Temporarily. Eve transformed into THE WINCHESTERS' MOTHER, Mary, to make them drop their guard. Furious, Dean told her that they did not work with monsters, and said "Bite me, bitch." Eve agreed and bit him, but Dean had not come unprepared, he and Sam had travelled back to the 1860s and thus killed a Phoenix and gotten its ashes; Phoenix ash being Eve's only weakness. EVE TRANSFORMED INTO BLACK GOO and melted. "Oh, what a world!"

Legacy
Eve lingered on in Season 7 in the series, when the Leviathans discussed mortal combat with their enemies, the vampires. The vampire chief said he was the son of Eve, and which the Leviathan said "Barely. A slut, not worthy of us. I knew Eve, and, frankly, your mummy was a whore." The vampire chief was furious and almost killed the Leviathan but Dean decapitated the Leviathan and killed him. Thus the vampires were saved!