Poison the Cup is a uncommon Instant card from Kaldheim (KHM), collector number 403. Current market price: $0.33 (foil $0.55), TCGplayer market prices via Scryfall.
Destroy target creature. If this spell was foretold, scry 2. Foretell {1}{B} (During your turn, you may pay {2} and exile this card from your hand face down. Cast it on a later turn for its foretell cost.)