Cursed Vampire

Flying
As Cursed Vampire enters the battlefield, you
may pay 1 life. If you do, put a -1/-1 counter on target creature.
At the beginning of each upkeep, you may pay 1 life. If you do, put a -1/-1 counter on target creature.
Cursed Vampire gets +1/+0 for each -1/-1 counter among creatures on the battlefield.