Mikaeus, the Unhallowed, Carnifex Demon, and Carrion Feeder

Prerequisites

• Mikaeus, the Unhallowed on the battlefield
• Carnifex Demon on the battlefield
• Carrion Feeder on the battlefield

Steps

1. Activate Carrion Feeder by sacrificing Carnifex Demon
2. Carnifex Demon dies, triggering its undying ability, returning it from your graveyard to the battlefield with a -1/-1 counter on it
3. Resolve the Carrion Feeder ability, putting a +1/+1 counter on it
4. Repeat

Results

• Infinite +1/+1 counters on Carrion Feeder
• Infinite death triggers
• Infinite ETB
• Infinite LTB
• Infinite sacrifice triggers