Dragotha is a powerful undead dragon known as a dracolich. He was formerly a powerful red dragon, the mightiest consort of Tiamat. At some point Dragotha offended his mistress, and was forced to leave Avernus. Making his way to Oerth, Dragotha fell in with Kyuss, and eventually became a dracolich and Kyuss' greatest servant. Dragotha's lair is thought to lie in the Wormcrawl Fissure, near Rift Canyon.
According to this history, Dragotha was forced into quiescence (inactivity) by Keraptis, the infamous wizard using a magical device called the Crown of Mortality.
An expedition to Dragotha's lair is told in the song "The Claws of Dragotha", which is believed to have been penned sometime in the 5th century CY