Surprise Party is a rare Enchantment card from Unfinity (UNF), collector number 29. Current market price: $0.11 (foil $0.18), TCGplayer market prices via Scryfall.
When this enchantment enters, yell "Surprise!" and put onto the battlefield any number of printed Clown Robot tokens that aren't touching each other, that you hid on the battlefield before you cast this enchantment, and that weren't spotted by an opponent before you cast this enchantment. Robots you control get +1/+0 and have vigilance.