Thrummingbird is a common Creature — Phyrexian Bird Horror card from Modern Masters 2015 (MM2), collector number 65. Current market price: $0.30 (foil $0.43), TCGplayer market prices via Scryfall.
Flying Whenever this creature deals combat damage to a player, proliferate. (Choose any number of permanents and/or players, then give each another counter of each kind already there.)