Necropolitan
A Necropolitan is a sapient undead creature native to the world of Dungeons & Dragons. Introduced in the Dungeons & Dragons 3rd Edition splatbook "Libris Mortis", in can be thought of as a variation on the older lich concept; a living creature who voluntarily transforms themselves into an undead being in order to achieve immortality, but without the obvious physical degeneration of the lich or the endless predatory nature of the vampire or ghoul.