Thought-Knot Seer is a rare Creature — Eldrazi card from Oath of the Gatewatch (OGW), collector number 9. Current market price: $5.16 (foil $9.82), TCGplayer market prices via Scryfall.
({C} represents colorless mana.) When this creature enters, target opponent reveals their hand. You choose a nonland card from it and exile that card. When this creature leaves the battlefield, target opponent draws a card.