Sacred Aqueduct
Land (Rare)

Sacred Aqueduct enters the battlefield tapped unless you reveal an artifact land card from your hand.

Tap: Add W or U to your mana pool.

Sacrifice Sacred Aqueduct: Add W or U to your mana pool.

2: Sacred Aqueduct becomes a 2/2 blue Merfolk creature until end of turn. It's still a land.

Justin Guay