Trained Arynx is a common Creature — Cat Beast Mount card from Outlaws of Thunder Junction (OTJ), collector number 36. Current market price: $0.16 (foil $0.20), TCGplayer market prices via Scryfall.
Whenever this creature attacks while saddled, it gains first strike until end of turn. Scry 1. (Look at the top card of your library. You may put that card on the bottom.) Saddle 2 (Tap any number of other creatures you control with total power 2 or more: This Mount becomes saddled until end of turn. Saddle only as a sorcery.)