Stalwart Successor + Ashnod's Altar + Lesser Masticore

Stalwart Successor

Ashnod's Altar

Lesser Masticore

How it works

1. Activate Ashnod's Altar by sacrificing Lesser Masticore
2. When Lesser Masticore dies, its persist ability triggers, returning it from your graveyard to the battlefield with a -1/-1 counter on it.
3. When Lesser Masticore enters, Stalwart Successor triggers, putting a +1/+1 counter on Lesser Masticore
4. Repeat.