Foul-Moon Wanderer

Lurk (At the beginning of your opponent's upkeep:
Tap this creature and put a lurk counter on it (Any creature with a lurk counter gains -1/-1 for every lurk counter on the battlefield). At the beginning of your
end step, you can exile this creature and place a lurk counter(s) that was on this creature on any target creature(s). When a creature with a lurk counter dies: Return this creature from exile to the battlefield.)
{b}{1}: Place a lurk counter on target creature.