The Aether Flues is a common Plane — Iquatana card from Planechase Planes (OHOP), collector number 2. Current market price: $2.75, TCGplayer market prices via Scryfall.
When you planeswalk to The Aether Flues and at the beginning of your upkeep, you may sacrifice a creature. If you do, reveal cards from the top of your library until you reveal a creature card, put that card onto the battlefield, then shuffle all other cards revealed this way into your library. Whenever chaos ensues, you may put a creature card from your hand onto the battlefield.