Boreas Charger is a rare Creature — Pegasus card from Commander 2018 (C18), collector number 1. Current market price: $0.28, TCGplayer market prices via Scryfall.
Flying When this creature leaves the battlefield, choose an opponent who controls more lands than you. Search your library for a number of Plains cards equal to the difference, reveal those cards, put one of them onto the battlefield tapped and the rest into your hand, then shuffle.