Grotmaw, Sewer of Corpses

At the beginning of your end step, you may exile
up to two creature cards at random from your opponents graveyards. Create an X/X black
zombie creature token with power and toughness
each equal to the total power and toughness of
the exiled cards and has all activated abilities of
the creatures exiled this way. If no creatures are
exiled this way, create a 4/4 black zombie
creature token.