Dragonskull Shores
Land (Rare)

When Dragonskull Shores enters the battlefield, sacrifice it unless you pay 3 life.

UB, Tap: Add BB, BU or UU to your mana pool.

1U: Dragonskull Shores becomes a 1/1 blue and black Horror Cleric creature with flying until end of turn. It's still a land.

Douglas Schuler