Slade Wilson, Deathstroke

Double strike, Deathtouch.
At the beginning of your upkeep, put a
bounty counter on target nontoken creature.
Whenever a creature with a bounty counter
on it dies, draw a card, then put a bounty
counter on another target nontoken creature.
"Maybe he is unkillable. I'll be damned if I try
something complicated when a bullet to the skull
will do the trick."