Onaraxis, the First Warlock, is an ancient black dragon born in the year 423 and responsible for starting the Great Infernal War.
In return for infernal power, Onaraxis made an implement for Asmodeus called the Siphon that allowed Asmodeus to send his massive army into Gaea in 963. During the war, Onaraxis was struck down and thought dead, but he escaped and polymorphed into a half-dragon, calling himself Arjhan. He survived under this disguise for years, even marrying and having two children: Dozren and Lozren. In 1129, he was killed by Dozren, but he wrote in his will that he wished to be resurrected.