({T}: Add {U} or {B}.) As this land enters, you may pay 2 life. If you don't, it enters tapped.

Until end of turn, target creature you control becomes a green Wurm with base power and toughness 6/4. Overload {4}{G}{G} (You may cast this spell for its overload cost. If you do, change "target" in its text to "each.")