Hollow Battlefield
Land-Swamp Mountain (Rare)

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

When Hollow Battlefield enters the battlefield, sacrifice it unless you pay R.

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

R, Tap: Target red creature gets +1/+0 until end of turn.

Mark Avon