Murasa Rootgrazer, Retreat to Coralhelm, and Yarok, the Desecrated

Prerequisites

• Murasa Rootgrazer on the battlefield
• Retreat to Coralhelm on the battlefield
• Yarok, the Desecrated on the battlefield
• At least one basic land in hand
• Murasa does not have summoning sickness

Steps

1. Tap Rootgrazer, putting a basic land into play
2. Retreat to Coralhelm triggers twice, in response, tap the basic for mana
3. Let the first Retreat trigger resolve, untapping Rootgrazer
4. Tap Rootgrazer, returning any basic you control to your hand
5. Let the second Retreat trigger resolve, untapping Rootgrazer
6. Repeat

Results

• Infinite colored mana
• Infinite landfall triggers