Lumra, Bellow of the Woods + Mirrorpool + Lithatog + Stone-Seeder Hierophant
Lumra, Bellow of the Woods
Mirrorpool
Lithatog
Stone-Seeder Hierophant
Infinite creature ETBInfinite death triggersInfinite self-millInfinite mana lands you control can produceInfinite landfall triggersPut all land cards from your library and graveyard onto the battlefieldInfinitely large creature until end of turn
How it works
Activate any number of other lands by tapping them, adding at least 4C.
Activate Lithatog by sacrificing a land except Mirrorpool.
Repeat step 2 until you control no lands except Mirrorpool.
Activate Mirrorpool's third ability by paying 4C, tapping and sacrificing it, creating a token copy of Lumra.
Put the Lumra token into your graveyard due to the legend rule.
The Lumra token's enters-the-battlefield ability triggers, causing you to mill four cards and return all land cards from your graveyard to the battlefield tapped.
When the lands enter the battlefield, Stone-Seeder Hierophant triggers that many times.
Resolve the first trigger, untapping Stone-Seeder Hierophant.
Holding priority, activate Stone-Seeder Hierophant by tapping it, untapping a land.