Thran Vigil + Carrion Feeder + Persistent Constrictor

Thran Vigil

Carrion Feeder

Persistent Constrictor

How it works

1. Activate Carrion Feeder by sacrificing Persistent Constrictor.
2. When Persistent Constrictor dies, its persist ability triggers, returning it from your graveyard to the battlefield with a -1/-1 counter on it.
3. Thran Vigil triggers, putting a +1/+1 counter on Persistent Constrictor.
4. Resolve the Carrion Feeder ability.
5. Repeat.

This clever loop is centered around Persistent Constrictor, which continuously cycles in and out of the graveyard thanks to its own persist ability. Each time it returns to the battlefield with a -1/-1 counter, Thran Vigil steps in to capitalize on the creature card leaving your graveyard, placing a +1/+1 counter on a creature you control. Because state-based actions cause +1/+1 and -1/+1 counters to annihilate each other, that -1/-1 counter is instantly neutralized, leaving the Constrictor completely clean and ready to be sacrificed all over again to Carrion Feeder.