Morrígan is the first vampire, named after the Irish goddess of war, death, and fate. She is a type of izichi; an eclectic group of beasts, curses, and humanoids created to terrorize sapient life.
Unlike the lesser vampires that would branch from her over the millennia, Morrígan cannot be killed, requires permission to turn someone, and fully ceases to exist in the daylight. She's more spirit than physical.