Consumed by the Catacombs

When Consumed by the Catacombs enters the battlefield, each creature gets -X/-X until end of
turn.
Whenever a creature an opponent controls dies,
you may pay 1 life, if you do, create a tapped
treasure token.
Whenever a creature you control dies, you may
pay 1 life, if you do, create a tapped 1/1 black
Skeleton creature token.