Gobsmacked is a common Enchantment — Aura card from Unfinity (UNF), collector number 11. Current market price: $0.06 (foil $0.14), TCGplayer market prices via Scryfall.
Enchant nonland permanent As this Aura enters, choose a person outside the game. As long as you can see the chosen person from your seat, enchanted permanent can't attack or block, and its activated abilities can't be activated.