The first hint at an actual costume came in the form of a video, where Klum was seen slipping into a bodysuit with the help of several friends.
She continued: "I thought it was fun to do a live art installation - that's what I just want to call it, because, for me, it's life art, what they do to me".
Yikes. This might be her most intense look yet.
Tom Kaulitz, left, and Heidi Klum in their costumes attend her Halloween party at Cathedrale on Thursday, Oct. 31, 2019, in NY.
"In my exposed brain?"
Klum held her famous party for the 20th time this year. Jonathan Van Ness dressed as a cat, Hunter McGrady went as Disney's Ariel, Halima Aden as Maleficent and Ice-T and Coco dressed as a character from "The Purge: Election Year" and Madonna, respectively.
Heidi - who was joined at the party at Cathedrale New York by the likes of Ice T, Coco Austin and Dylan Sprouse - made a decision to give fans a behind-the-scenes look into her costume preparations this year, as she prepared for her party by getting ready in the window of a store in the Big Apple.
The party also drew in a number of fashion designers, including Joseph Altuzarra, who with husband Seth Weissman dressed as "leather daddies" in anticipation of becoming fathers in three weeks, and The Blonds designers David and Phillipe Blond, who dressed as Batman and Catwoman, respectively. All we know is that it was otherworldly - and completely terrifying.