$35.10 @ TCGplayer
When The Meathook Massacre enters the battlefield, each creature gets -X/-X until end of turn.
Whenever a creature you control dies, each opponent loses 1 life.
Whenever a creature an opponent controls dies, you gain 1 life.
If The Meathook Massacre enters the battlefield and it wasn't cast (or it was cast without paying its mana cost), X will be 0. The first ability will trigger, but it won't be much of a massacre.
