Celestial Colonnade (UMA) from Ultimate Masters, available at 401 Games Canada.

• Rarity: Rare
• Finish: Normal
• Artist: Eric Deschamps
• Card Text:
  Celestial Colonnade enters the battlefield tapped.
  T: Add W or U.
  3WU: until end of turn, Celestial Colonnade becomes a 4/4 white and blue Elemental creature with flying and vigilance. It's still a land.