Sulfurous-land
Land (Rare)

Sulfurous-land enters the battlefield tapped.

Tap: Add W or B to your mana pool.

Sacrifice Sulfurous-land: Add W or B to your mana pool.

WB: Sulfurous-land becomes a 2/1 black and white Specter creature until end of turn. It's still a land.

Christopher Prescott