What is "baelnorn"

A baelnorn is a fictional undead creature, usually a spellcaster, in the Dungeons & Dragons fantasy role-playing game.

Baelnorns are described as elves who sought undeath to serve their families, communities, or other purposes (usually to see a wrong righted or to achieve a certain magical discovery or deed). They are lich-like creatures that appear as impressive-looking elves with shriveled skin and glowing white eyes. Most of their appearances in modules, setting books, games, novels and the like are related to the old lords of Cormanthor/ Myth Drannor, a fictional location in the Forgotten Realms campaign setting.