Necromaster Dragon is a rare Creature — Dragon card from Dragons of Tarkir (DTK), collector number 226. Current market price: $0.29 (foil $0.61), TCGplayer market prices via Scryfall.
Flying Whenever this creature deals combat damage to a player, you may pay {2}. If you do, create a 2/2 black Zombie creature token and each opponent mills two cards.