Death's-Head Buzzard

Flying
When this creature dies, all creatures get -1/-1 until end of turn.

Death Bomb

As an additional cost to cast this spell, sacrifice a creature.
Destroy target nonblack creature. It can't be regenerated. Its controller loses 2 life.

Death Cloud

Each player loses X life, discards X cards, sacrifices X creatures of their choice, then sacrifices X lands of their choice.

Apocalypse Demon

Flying
Apocalypse Demon's power and toughness are each equal to the number of cards in your graveyard.
At the beginning of your upkeep, tap this creature unless you sacrifice another creature.