Appa, Loyal Sky Bison is a uncommon Legendary Creature — Bison Ally card from Avatar: The Last Airbender (TLA), collector number 9. Current market price: $0.25 (foil $0.35), TCGplayer market prices via Scryfall.
Flying Whenever Appa enters or attacks, choose one — • Target creature you control gains flying until end of turn. • Airbend another target nonland permanent you control. (Exile it. While it's exiled, its owner may cast it for {2} rather than its mana cost.)