Spawning Pit + Rocksteady, Mutant Marauder

Spawning Pit

Rocksteady, Mutant Marauder

How it works

1. Activate Spawning Pit by sacrificing the persist creature.
2. When the persist creature dies, its persist ability triggers, returning it from your graveyard to the battlefield with a -1/-1 counter on it.
3. When the persist creature enters, Rocksteady triggers, putting a +1/+1 counter on that creature.
4. Resolve the Spawning Pit ability.
5. Repeat