Mikaeus, the Unhallowed + Putrid Goblin + Carrion Feeder

Mikaeus, the Unhallowed

Putrid Goblin

Carrion Feeder

How it works

1. Activate Carrion Feeder by sacrificing Putrid Goblin.
2. When Putrid Goblin dies, its persist ability triggers, returning it from your graveyard to the battlefield with a -1/-1 counter on it.
3. Resolve the Carrion Feeder ability.
4. Activate Carrion Feeder by sacrificing Putrid Goblin.
5. When Putrid Goblin dies, its undying ability triggers, returning it from your graveyard to the battlefield with a +1/+1 counter on it.
6. Resolve the Carrion Feeder ability.
7. Repeat.

This clever loop relies on the constant counter-cancellation between Putrid Goblin's persist ability and Mikaeus, the Unhallowed granting it undying. When you sacrifice Putrid Goblin to Carrion Feeder, persist returns it with a -1/-1 counter, but when it dies again, the newly applied +1/+1 counter from Mikaeus's static buff annihilates that -1/-1 counter as a state-based action, allowing undying to trigger the next time it hits the graveyard. Carrion Feeder acts as the dedicated sacrifice outlet that fuels the engine, letting you repeat this cycle endlessly to generate boundless growth and triggers.