In the "Forgotten Realms" campaign setting, dragons are very close to the ones in Dragonlance. A sect of cultists called the "Cult of the Dragon" believes that dragons, particularly undead ones, will rule the world, and are trying to persuade evil dragons to become "dracoliches" -- undead lich-like dragons, which are partially bound to the cult by the rituals which grant them their undead status. Additionally, in the "D&D" supplement book "The Draconomicon", several other undead varieties of the dragon – ghost, skeleton, vampire, and zombie dragons – are described.