Aetherstream Leopard (Foil) (AER) from Aether Revolt, available at 401 Games Canada.

• Rarity: Common
• Finish: Foil
• Artist: Winona Nelson
• Card Text:
  Trample
  When Aetherstream Leopard enters the battlefield, you get E (an energy counter).
  Whenever Aetherstream Leopard attacks, you may pay E. If you do, it gets +2/+0 until end of turn.