Waterveil Prairie
Land (Rare)

Waterveil Prairie enters the battlefield tapped unless you sacrifice a nonbasic land.

Tap: Add U to your mana pool. If you played a land this turn, Add W to your mana pool instead.

1U: Waterveil Prairie becomes a 1/1 white and blue Crab creature with flying until end of turn. It's still a land.

Douglas Chippy