Retreat to Coralhelm, Rakdos Carnarium, and PuPu UFO

Prerequisites

• Retreat to Coralhelm on the battlefield
• Rakdos Carnarium in hand
• PuPu UFO on the battlefield

Steps

1. Activate PuPu UFO by tapping it, putting Rakdos Carnarium from your hand onto the battlefield
2. When Rakdos Carnarium enters the battlefield, it and Retreat to Coralhelm trigger
3. Resolve the Rakdos Carnarium 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