Screams from Within, Umbral Collar Zealot, and Garrison Excavator

Prerequisites

• Screams from Within on the battlefield
• Umbral Collar Zealot on the battlefield
• Garrison Excavator on the battlefield

Steps

1. Activate Umbral Collar Zealot by sacrificing the creature that has Screams from Within attached
2. When the creature dies, Screams from Within triggers, returning it from your graveyard to the battlefield attached to another creature you control
3. Garrison Excavator triggers, creating a creature token
4. Resolve the Umbral Collar Zealot ability
5. Repeat

Results

• Infinite ETB
• Infinite LTB
• Infinite death triggers
• Infinite sacrifice triggers
• Infinite surveil