Shadow Maw

When Shadow Maw enters the battlefield,
non-black creatures get -1/-1 until end of turn.
At the beginning of your upkeep, you may pay {1}{b}. If you do, create a 1/1 black Shadow
creature token with "Sacrifice this: target
creature gains indestructible until end of turn."
Whenever Shadow Maw deals combat damage to
a player, they discard a card.