Tidal-wood
Land (Rare)

Tidal-wood enters the battlefield tapped unless you control three or more enchantments.

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

1U: Tidal-wood becomes a 1/1 green and blue Crab creature with flying until end of turn. It's still a land.

Rebecca Moeller