Unnatural Hunger is a rare Enchantment — Aura card from Mercadian Masques (MMQ), collector number 169. Current market price: $2.63 (foil $11.13), TCGplayer market prices via Scryfall.
Enchant creature At the beginning of the upkeep of enchanted creature's controller, this Aura deals damage equal to that creature's power to that player unless they sacrifice another creature of their choice.