Obsidian Hold
Land (Rare)

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

Tap: Add BR to your mana pool. Obsidian Hold doesn't untap during your next untap step.

1R: Obsidian Hold becomes a 1/1 black and red Rat creature with first strike until end of turn. It's still a land.

John Tedin