Tiamat

According to legend, Tiamat is the creator of dragons, and is sometimes called the "mother" of dragons. This is hyperbole, though, since Tiamat is genderless.

History
Tiamat was one of the Ascended, who gained favor with The Creator in the time before the Age of Deception. As the legend goes, Tiamat was one of the Ascended who followed Immaru across the Astral Sea and planted a Great Tree, allowing herself to communicate with her followers in the material plane.

At some point, Tiamat shaped and created the dragons, her vicious and unfailingly loyal defenders.

Later, her chief rival, Immaru, began a war among the Ascended. If anyone was winning, it was Tiamat, at least for a time.

But Immaru used his cunning and guile to convert many of Tiamat's dragons to his cause. To tip the balance in his favor, Immaru armed them with the Razors, legendary weapons of great power that could cut down Great Trees. One by one his armies destroyed the Great Trees, until only Immaru's and Tiamat's were left.

Because dragons couldn't harm Tiamat, Immaru had no choice but to leave her alive, and her tree standing. But Tiamat had been cornered, exiled and silenced, never to be heard from by the material plane again.

A thousand years later, when the Four Knights -- St. Thoril, St. Alelion, St. Kolyani, and St. Aelena -- embarked on their crusade to destroy the Great Trees and end Immaru's deception, they battled and defeated Tiamat, destroying her tree, and killing the remaining dragons in the material plane.