Altar of Dementia + Lesser Masticore + Hardened Academic

Altar of Dementia

Lesser Masticore

Hardened Academic

How it works

1. Activate Altar of Dementia 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. Hardened Academic triggers, putting a +1/+1 counter on Lesser Masticore.
4. Resolve the Altar of Dementia ability.
5. Repeat.