Rally of the Graves

Preparation ( you may put cards with preparation onto the battlefield at the beginning of the game or in a certain phase.)
Rally of the Graves enters the battlefield with twelve time counters on it. At the beginning of your upkeep. Remove a time counter from Rally
of the Graves. When Rally of the Graves has no more time counters on it. Put twelve 2/2 black zombie creature tokens on the battlefield and put five time counters on Rally of the Graves.