Monastery Flock is a common Creature — Bird card from Khans of Tarkir (KTK), collector number 47. Current market price: $0.09 (foil $0.37), TCGplayer market prices via Scryfall.
Defender, flying Morph {U} (You may cast this card face down as a 2/2 creature for {3}. Turn it face up any time for its morph cost.)