Pestilent Ghoul

Blight (Whenever a creature blocks this creature, this creature gets +1/+1 until end of turn and the blocking creature gets -1/-1 until end of turn.)
Whenever a creature with total toughness less
than its base toughness dies, its controller gets a
poison counter. That player may pay {b} or three
life to prevent this effect.
They don't need to kill you. One scratch, and they
wait for you to die on your own.