Magic 2012

Call to the Grave

At the beginning of each player's upkeep, that player sacrifices a non-Zombie creature.
At the beginning of the end step, if no creatures are on the battlefield, sacrifice Call to the Grave.

At the beginning of each player's upkeep, that player sacrifices a non-Zombie creature of their choice.
At the beginning of the end step, if no creatures are on the battlefield, sacrifice Call to the Grave.

Scourge

At the beginning of each player's upkeep, that player sacrifices a non-Zombie creature.
At end of turn, if no creatures are in play, sacrifice Call to the Grave.