Up close, it was possible to make out two rows of sharply pointed false teeth that made her costume more killer robot than caped crusader. But a superhero she was, flowing fuchsia wig and all.
And her husband Seal, in a metallic silver muscle suit, was her sidekick. "He's the Silver Surfer," she said cheerfully.
Klum's costume, which required the skill of a stilt-walker with its two-foot high boot extensions, was created with the help of her frequent collaborator, designer Martin Izquierdo. The theatrical specialist also assisted Miss Universe, Ximena Navarrete, with her costume -- the universe.
Those celebrities and many others (like John Legend and his girlfriend Chrissy Teigen, who came as Antony and Cleopatra) were at Lavo in New York City to attend Heidi's party, which was presented by AOL. Questlove of The Roots acted as celebrity deejay.
Kim Kardashian walked the red carpet dressed as Little Red Riding Hood. She said she was excited to be in NYC for the opening of the Manhattan branch of Dash, the clothing boutique she owns with her sisters.
She was flanked by her friends and stars of the E! spinoff show "The Spin Crowd," Jonathan Cheban as the Big Bad Wolf, and Simon Huck as, well, a man in a suit. (Although he did score Halloween points for having an eyeball filled with real blood, on account of recent Lasik surgery.)
Newly minted "Project Runway" winner Gretchen Jones came as Amelia Earhart, along with season six winner Irina Shabayeva.
Season four winner Christian Siriano and his boyfriend came dressed as the dancing feather duster and candlestick from "Beauty and the Beast." "I made the interns do it," Siriano said of fabricating the costumes at his design studio.
Other designers present included Rebecca Minkoff (as Frida Kahlo) and Marc Bouwer, wearing a kind of futuristic, gender-bending cabaret ensemble.
Sports Illustrated model Brooklyn Decker (aka Mrs. Andy Roddick) came in a troll costume, while Lorenzo Martone (the most recent ex-Mr. Marc Jacobs), dressed as Jesus, came with models Julie Henderson, Jessica White and Fernanda Mota.
Russell Simmons -- who used to date Henderson -- came as Jam Master Jay, in honor of the eighth anniversary of the Run-DMC member's death, which fell on the weekend.
Ice-T came in a mad scientist costume with his wife Coco, dressed as a nurse. The busty model, who is known for her revealing outfits, joked that she didn't normally need an excuse to dress up. "But I actually went shopping for this one!" she insisted.
For more Halloween with Heidi, check our Klum's costumes though the years.
Meanwhile, see how the Obamas celebrated Halloween at the White House.
And click here for more celebrity Halloween costumes.