Zoetic Cavern (CMA) from Commander Anthology, available at 401 Games Canada.

• Rarity: Uncommon
• Finish: Normal
• Artist: Lars Grant-West
• Card Text:
  T: Add C to your mana pool.
  Morph 2 (You may cast this card face down as a 2/2 creature for 3. Turn it face up any time for its morph cost.)