Kotis, the Fangkeeper is a rare Legendary Creature — Zombie Warrior card from Tarkir: Dragonstorm Promos (PTDM), collector number 202p. Current market price: $0.77 (foil $2.40), TCGplayer market prices via Scryfall.
Indestructible Whenever Kotis deals combat damage to a player, exile the top X cards of their library, where X is the amount of damage dealt. You may cast any number of spells with mana value X or less from among them without paying their mana costs.