Drowned Veldt
Land (Rare)

When Drowned Veldt enters the battlefield, sacrifice it unless you pay U.

1, Tap: Add UU, UG or GG to your mana pool. Drowned Veldt deals 1 damage to you.

GU: Drowned Veldt becomes a 2/1 blue and green Crab creature until end of turn. It's still a land.

Mark Tedin