When Necromancer's Covenant enters the battlefield, exile all creature cards from target player's graveyard, then create a 2/2 black Zombie creature token for each card exiled this way.
Zombies you control have lifelink.
When Necromancer's Covenant comes into play, remove all creature cards in target player's graveyard from the game, then put a 2/2 black Zombie creature token into play for each card removed this way.
Zombies you control have lifelink.
--This card has no flavor text --