Malignus is a mythic Creature — Elemental Spirit card from Avacyn Restored (AVR), collector number 148. Current market price: $6.73 (foil $19.37), TCGplayer market prices via Scryfall.
Malignus's power and toughness are each equal to half the highest life total among your opponents, rounded up. Damage that would be dealt by this creature can't be prevented.