Retreat to Coralhelm + Murasa Rootgrazer + Trench Behemoth

Retreat to Coralhelm

Murasa Rootgrazer

Trench Behemoth

How it works

1. Activate a basic land you control by tapping it, adding at least 1.
2. Activate Trench Behemoth by returning the basic land from the battlefield to your hand, untapping Trench Behemoth.
3. Activate Murasa Rootgrazer's first ability by tapping it, putting the basic land from your hand onto the battlefield.
4. The land enters the battlefield, triggering Retreat to Coralhelm, untapping Murasa Rootgrazer.
5. Repeat.