Obzoroul the Deathless

Zombies are clerics in addition to there other
types.
Whenever another cleric or zombie creature you
control dies, return it to the battlefield under its
owner's control with a -1/-1 counter on it for each
time a creature with that same name entered the
battlefield. If a creature enters the battlefield with
a number of counters on it equal to its toughness,
exile it and you lose life equal to its mana value.