The death spell in Harry Potter is the Killing Curse, also known as Avada Kedavra. It is one of the three Unforgivable Curses outlawed under wizarding law. The Killing Curse kills the victim instantaneously and painlessly, usually with a blinding flash of green light. There is no way to block the spell, and there is no counter-curse - it can only be dodged. Harry Potter is the only known survivor of the Curse, having been protected by his mothers sacrifice - the spell instead rebounded upon the caster, Lord Voldemort. The Curse leaves a victims body completely unmarked, with their final expression frozen on their face. The Killing Curse is considered to be one of the most terrible curses in the wizarding world.