Rot Gorge
Land-Swamp Mountain (Rare)

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

Rot Gorge enters the battlefield tapped unless you sacrifice a monocolored permanent.

BB, Tap, Sacrifice Rot Gorge: Put a -1/-1 counter on target creature.

2, Tap: Target land becomes a 3/3 red Elemental creature until end of turn. It's still a land.

Christopher Palck