Abandoned Tubes
Land-Plains Swamp (Rare)

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

Abandoned Tubes enters the battlefield tapped unless you reveal a monocolored card from your hand.

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

BB, Tap, Sacrifice Abandoned Tubes: Put a -1/-1 counter on target creature.

Carl Myrfors