Bison Whistle is a rare Artifact card from Avatar: The Last Airbender Eternal (TLE), collector number 202. Current market price: $0.35 (foil $0.36), TCGplayer market prices via Scryfall.
{1}, {T}: Look at the top card of your library. If it's a Bison card, you may put it onto the battlefield. If it's a creature card, you may reveal it and put it into your hand. Otherwise, you may put it into your graveyard.