Stalwart Successor + Umbral Collar Zealot + Scuzzback Marauders

Stalwart Successor

Umbral Collar Zealot

Scuzzback Marauders

How it works

1. Activate Umbral Collar Zealot by sacrificing Scuzzback Marauders
2. When Scuzzback Marauders dies, its persist ability triggers, returning it from your graveyard to the battlefield with a -1/-1 counter on it.
3. When Scuzzback Marauders enters, Stalwart Successor triggers, putting a +1/+1 counter on Scuzzback Marauders
4. Resolve the Umbral Collar Zealot ability.
5. Repeat.