Earthcraft + Sliver Queen + Lavaleaper

Earthcraft

Sliver Queen

Lavaleaper

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 land.
3. Activate the land by tapping it, adding 1
4. Lavaleaper triggers, adding 1
5. Repeat

This cunning engine relies on a brilliant mana-generation loop enabled by Lavaleaper's static ability, which ensures all your creatures naturally enter the battlefield with haste and can be tapped right away. You use Earthcraft to tap the newborn token created by Sliver Queen, untapping a basic land in the process. When that land is tapped for mana, Lavaleaper triggers to double your yield, neatly covering the activation cost needed to repeat the cycle indefinitely.