Thrummingbird (CM2) from Commander Anthology Volume II, available at 401 Games Canada.

• Rarity: Uncommon
• Finish: Normal
• Artist: Efrem Palacios
• Card Text:
  Flying
  Whenever Thrummingbird deals combat damage to a player, proliferate. (You choose any number of permanents and/or players with counters on them, then give each another counter of a kind already there.)