Vampire

A Vampire is a form of supernatural creature created through a curse that can be passed from one Vampire to a living being. Though not techincally dead — in fact, being far too alive — they are enshrouded by necromantic energy resulting in them being classified as "Undead." Vampires are terrifyingly powerful beings, capable of supernatural strength, speed, and magical talent. They have a preternatural ability to command Undead, and to instill fear in those who behold them.
Lesser Vampires, known as "Vampire Spawn" can be created through a debased form of the curse. These creatures are still deadly, but entirely beholden to their creators.
Strahd von Zarovich is believed to be the first Vampire, and the progenitor of their species. How he came to the curse is unknown.