Alquist Proft, Master Sleuth is a mythic Legendary Creature — Human Detective card from Murders at Karlov Manor (MKM), collector number 384. Current market price: — (foil $1.47), TCGplayer market prices via Scryfall.
Vigilance When Alquist Proft enters, investigate. (Create a Clue token. It's an artifact with "{2}, Sacrifice this token: Draw a card.") {X}{W}{U}{U}, {T}, Sacrifice a Clue: You draw X cards and gain X life.