Carrion Feeder, Hardened Academic, and Obstinate Gargoyle

Prerequisites

• Carrion Feeder on the battlefield
• Hardened Academic on the battlefield
• Obstinate Gargoyle on the battlefield

Steps

1. Activate Carrion Feeder by sacrificing Obstinate Gargoyle
2. When Obstinate Gargoyle 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 Obstinate Gargoyle
4. Resolve the Carrion Feeder ability
5. Repeat

Results

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