Stalwart Successor + Shilgengar, Sire of Famine + Grazing Kelpie

Stalwart Successor

Shilgengar, Sire of Famine

Grazing Kelpie

How it works

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