Retreat to Coralhelm + Gruul Turf + PuPu UFO

Retreat to Coralhelm

Gruul Turf

PuPu UFO

How it works

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