Nantuko Monastery (ARC) from Archenemy, available at 401 Games Canada.

• Rarity: Uncommon
• Finish: Normal
• Artist: Rob Alexander
• Card Text:
  T: Add 1 to your mana pool.
  Threshold — GW: Nantuko Monastery becomes a 4/4 green and white Insect Monk creature with first strike until end of turn. It's still a land. Activate this ability only if seven or more cards are in your graveyard.