Krosan Depths
Land (Rare)

Krosan Depths enters the battlefield tapped unless you control one or more creatures.

Tap, Pay 1 life: Add B or G to your mana pool.

1, Tap, Sacrifice Krosan Depths: Draw a card.

2G: Krosan Depths becomes a 2/2 black and green Bear creature with trample until end of turn. It's still a land.

Greg Briclot