Earthcraft + Keeper of Progenitus + Sliver Queen

Earthcraft

Keeper of Progenitus

Sliver Queen

How it works

1. Activate Sliver Queen by paying 2, creating a creature token
2. Activate Earthcraft by tapping the creature token, untapping a basic Mountain, Forest or Plains.
3. Activate the land by tapping it, adding 1
4. Keeper of Progenitus triggers, adding 1
5. Repeat

This clever loop is fueled by Earthcraft, which lets you tap any newly minted creature token to untap a basic Mountain, Forest, or Plains and instantly jumpstart your mana production. Whenever that basic land is tapped, Keeper of Progenitus doubles your yield by tossing in an extra mana of any type that land produced, turning a single tap into a net gain. That surplus mana feeds right back into Sliver Queen to generate another 1/1 colorless Sliver creature token, keeping the engine running indefinitely.