Ghoulcaller's Storehouse

Whenever a nontoken creature you control dies, put a storage counter on Ghoulcaller's Storehouse.
Sacrifice a nontoken creature: Put two 2/2 black Zombie creature tokens onto the battlefield.
Sacrifice Ghoulcaller's Storehouse: Put X 2/2 black Zombie creature tokens onto the battlefield, where X is the number of storage counters on it.