Carrion Feeder + Grazing Kelpie + Hardened Academic

WUBRG identity

Commander legal

The 3 combo pieces

• Carrion Feeder
• Grazing Kelpie
• Hardened Academic

How to execute it

1. Activate Carrion Feeder 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. Hardened Academic triggers, putting a +1/+1 counter on Grazing Kelpie.
4. Resolve the Carrion Feeder ability.
5. Repeat.

What the combo produces

• Infinite +1/+1 counters on a creature
• Infinite creature LTB
• Infinite death triggers
• Infinite ETB
• Infinite sacrifice triggers