Tawnos's Coffin is a rare Artifact card from Antiquities (ATQ), collector number 68. Current market price: $112.50, TCGplayer market prices via Scryfall.
You may choose not to untap this artifact during your untap step. {3}, {T}: Exile target creature and all Auras attached to it. Note the number and kind of counters that were on that creature. When this artifact leaves the battlefield or becomes untapped, return that exiled card to the battlefield under its owner's control tapped with the noted number and kind of counters on it. If you do, return the other exiled cards to the battlefield under their owner's control attached to that permanent.