Grim Poppet, Dack's Duplicate, and Flourishing Defenses

Prerequisites

• Grim Poppet on the battlefield
• Dack's Duplicate on the battlefield
• Flourishing Defenses on the battlefield

Steps

1. Activate Grim Poppet by removing a -1/-1 counter from it, putting a -1/-1 counter on Dack's Duplicate
2. Flourishing Defenses triggers, creating a creature token
3. Activate Dack's Duplicate by removing a -1/-1 counter from it, putting a -1/-1 counter on Grim Poppet
4. Flourishing Defenses triggers, creating a creature token
5. Repeat

Results

• Infinite ETB
• Infinite creature tokens