Overgrown Catacombs
Land-Swamp Forest (Rare)

(Tap: Add B or G to your mana pool.)

When Overgrown Catacombs enters the battlefield, sacrifice it unless you pay 1 life.

BG: Overgrown Catacombs becomes a 2/1 green and black Stag creature until end of turn. It's still a land.

Christopher Grant West