Lava Barrens
Land-Swamp Mountain (Rare)

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

When Lava Barrens enters the battlefield, sacrifice it unless you pay 1 life.

RR, Tap: Target red creature gets +1/+1 until end of turn.

1, Tap: Target land becomes a 2/2 black Rat creature until end of turn. It's still a land.

Steve Briclot