What goes bump in the night? Vampires, ghosts, and supermodels as far as the eye can see. On Saturday night, Natalia Vodianova brought her Fabulous Fund Fair to New York City, and in turn, hosted the most truly over-the-top—and totally fun—Halloween party of the year. Hosted by the models’ Naked Heart Foundation and amfAR, the event transformed the event space Skylight Clarkson North into a haunted carnival—art-directed by Jeff Koons, no less. But this was no typical country fair. There were Louis Vuitton-branded bumper cars, performances by Nas and Charli XCX, and endless booths of interactive games, sponsored by the likes of Net-A-Porter, Sergio Rossi, Chopard, Veuve Cliquot, and Givenchy, where the prizes were actual designer goods (sure beats a stuffed bear). Taking it all in—all while wearing their best costumed attire—were Karlie Kloss, dressed as a convincing Marilyn Monroe, Paris Hilton, Brooklyn Beckham, Mariacarla Boscono, Carolyn Murphy, Teyana Taylor, and even a stray Sprouse twin. Here, a look inside the festivities.