Stalwart Successor + Trapjaw Kelpie + Carrion Feeder

Stalwart Successor

Trapjaw Kelpie

Carrion Feeder

How it works

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

This clever loop lets you feed Trapjaw Kelpie to Carrion Feeder over and over, turning the Kelpie's own resurrection into a permanent engine. Normally, Trapjaw Kelpie's persist ability would bring it back with a -1/+1 neutralizing -1/-1 counter that prevents further persist loops, but that's where Stalwart Successor comes to the rescue with its clever static trigger. Every single time those -1/-1 counters arrive, Stalwart Successor intercepts the very first instance of counters being placed on a creature each turn and tacks on a +1/+1 counter instead, instantly annihilating the -1/-1 counter and resetting the Kelpie for another round.