Horde Of The Masses

When Horde Of The Masses enters the battlefield, put {x} 2/2 zombie creature tokens into play.
{b}: Sacrifice a zombie: Return Horde Of The Masses from your graveyard to your hand.
Rebuild (When you sacrifice a creature, put a +1/+1 counter on this creature for each other creature in play with a +1/+1 counter.)