Feed on the Sap

Enchant land
When enchanted land becomes tapped, you may add one Mana of any color that this land can produce to your Mana pool, unless its controller pays 2 life. If he or she does, that land does not untap during its controller next untap step.
"Pesky critters. Just you wait 'til I find my musket."
- Senior Mage Yoon