A baby Zombie Norn.
From their shallow graves they rise moaning, waiting to feast on the brain of another creature, never alive, but never dead. No one knows how they can move, or where they are going next, but live in fear of them every day. They require no food, and can not die of old age on their own, and their only weaknesses are that they do not age without outside help, and once aged die after a period of time. Watch out, because if you're not careful, you may find yourself being eaten by a Zombie Norn.
The Zombie Norns are a green tinted undead breed created by Empyreal. They lack any chemical for life, and yet continue to live, thus undead. They are extremely succeptible to diseases, which decay them. They do not age, but can be injected with a growth hormone, chemical 14, to make them age to adult. As babies, they have an insatiable appetite to fuel the growth hormone, and as adults are eternally friendly. Despite being so friendly, they never seem to overpopulate the world. Babies will never die of old age, but once they are injected with chemical 14, they should die in about an hour. They also have almost no need to sleep, but occasionally will rest.