Retreat to Coralhelm, Izzet Boilerworks, and PuPu UFO

Prerequisites

• Retreat to Coralhelm on the battlefield
• Izzet Boilerworks in hand
• PuPu UFO on the battlefield

Steps

1. Activate PuPu UFO by tapping it, putting Izzet Boilerworks from your hand onto the battlefield
2. When Izzet Boilerworks enters the battlefield, it and Retreat to Coralhelm trigger
3. Resolve the Izzet Boilerworks trigger, returning itself from the battlefield to your hand
4. Resolve the Retreat to Coralhelm trigger, untapping PuPu UFO
5. Repeat

Results

• Infinite landfall triggers