Simic Keyrune (GTC) from Gatecrash, available at 401 Games Canada.

• Rarity: Uncommon
• Finish: Normal
• Artist: Daniel Ljunggren
• Card Text:
  T: Add G or U to your mana pool.
  GU: Simic Keyrune becomes a 2/3 green and blue Crab artifact creature with hexproof until end of turn.