Otar the Foul

This creature gains +1/+1 for each undead creature on the battlefield and in the graveyard.
Whenever this creature attacks, you may put target creature from your graveyard onto the battlefield. It gains undead in addition to it's other subtypes.
Whenever Otar the Foul deals damage to a player, or kills a defending creature, summon a 2/2 Black Zombie token creature.