Steppe Catacombs
Land (Rare)

At the beginning of your end step, if you didn't cast any spells this turn, Steppe Catacombs deals 1 damage to you.

Tap: Add W or B to your mana pool.

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

Lars Deschamps