Thijarian Witness is a uncommon Creature — Alien Cleric card from Doctor Who (WHO), collector number 111. Current market price: $0.20 (foil $0.20), TCGplayer market prices via Scryfall.
Flash Bear Witness — Whenever another creature dies, if it was attacking or blocking alone, exile it and investigate. (Create a Clue token. It's an artifact with "{2}, Sacrifice this token: Draw a card.")