Cursed-works
Land (Rare)

Cursed-works enters the battlefield tapped unless you reveal an artifact land card from your hand.

Tap: Add U or B to your mana pool.

Sacrifice Cursed-works: Add U or B to your mana pool.

UB: Cursed-works becomes a 2/1 black and blue Specter Rat creature until end of turn. It's still a land.

Allan Myrfors