Rotting Fields
Land (Rare)

Whenever Rotting Fields becomes tapped, it deals 1 damage to you.

Tap: Add B to your mana pool. Activate this ability only if you control a Swamp.

Tap: Add W to your mana pool. Activate this ability only if you control a Plains.

1W: Rotting Fields becomes a 0/4 white and black Zombie creature with defender until end of turn. It's still a land.

Kev Prescott