Ethereal Investigator is a rare Creature — Spirit card from Murders at Karlov Manor Commander (MKC), collector number 105. Current market price: $0.42, TCGplayer market prices via Scryfall.
Flying When this creature enters, investigate X times, where X is the number of opponents you have. (To investigate, create a Clue token. It's an artifact with "{2}, Sacrifice this token: Draw a card.") Whenever you draw your second card each turn, create a 1/1 white Spirit creature token with flying.