Havenwood Pools
Land (Rare)

Havenwood Pools enters the battlefield tapped unless you control five or more creatures.

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

GU: Havenwood Pools becomes a 2/1 green and blue Treefolk creature until end of turn. It's still a land.

Christopher Guay