Chevill, Bane of Monsters

Deathtouch
At the beginning of your upkeep, if your
opponents control no permanents with bounty counters on them, put a bounty
counter on target creature or planeswalker an opponent controls.
Whenever a permanent an opponent controls
with a bounty counter on it dies (is put into the graveyard from the battlefield), you gain 3 life
and draw a card.