Thornbite Staff, Grimgrin, Corpse-Born, and Godsire

Prerequisites

• Thornbite Staff on the battlefield
• Grimgrin, Corpse-Born on the battlefield
• Godsire on the battlefield

Steps

1. Activate Godsire by tapping it, creating a creature token
2. Activate Grimgrin by sacrificing the creature token
3. When the creature token dies, Godsire triggers due to its ability granted to it by Thornbite Staff, untapping Godsire
4. Resolve the Grimgrin ability, putting a +1/+1 counter on Grimgrin and untapping it Repeat

Results

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