Mistway Spy (MKM) from Murders at Karlov Manor, available at 401 Games Canada.

• Rarity: Uncommon
• Finish: Normal
• Artist: Andrew Mar
• Card Text:
  Flying
  Disguise 1U (You may cast this card face down for 3 as a 2/2 creature with ward 2. Turn it face up any time for its disguise cost.)
  When Mistway Spy is turned face up, until end of turn, whenever a creature you control deals combat damage to a player, investigate.