Raging Ravine (UMA) from Ultimate Masters, available at 401 Games Canada.

• Rarity: Rare
• Finish: Normal
• Artist: Todd Lockwood
• Card Text:
  Raging Ravine enters the battlefield tapped.
  T: Add R or G.
  2RG: Until end of turn, Raging Ravine becomes a 3/3 red Elemental creature with "Whenever this creature attacks, put a +1/+1 counter on it." It's still a land.