The German model and TV star, who hits the New York bash every year, teased her much-anticipated look hours before prosthetics artist Mike Marino completed the look – which included a blinking head resting on top of hers.
Klum and Kaulitz posed with her daughter Leni Klum, who followed suit with an otherworldly transformation that included white body paint, antennae and glasses to create an alien effect.
Posting a video of the pair on Instagram, Klum wrote: “Heidi Halloween 2024. Out of this world.”
It wasn’t the first alien-inspired costume this Halloween, with American singer Janelle Monae also portraying the alien in a series of transformative photos shared on Instagram.
Monae captured moments from the film, including a glowing finger and heart, while she also posed as the character wrapped in a blanket, captioning the snaps: “ET returns 42 years later.”
Klum and Monae weren’t the only famous faces to get into the Halloween spirit, with Kim Kardashian following the trend for a full-body transformation this year.
The reality star and entrepreneur embraced a reptilian look in a white scaly suit paired with a prosthetic head, green eyes, clawed hands and feet with a long spiked tail set in a swamp.
“Albino alligator,” she wrote on Instagram.
Styled by artist Alexis Stone, Kardashian shared close-up videos of the look along with photos of the elaborate prosthetics before they were attached to her body.
Meanwhile, Kardashian sister Kylie Jenner transformed into American actress Demi Moore from her 1996 hit film Striptease.
The American star stripped down to recreate the film’s poster, complete with windswept long straight hair with a fringe and Moore’s natural make-up.
Kendall Jenner and Hailey Bieber also paid tribute to a poster in tribute to Paris Hilton and Nicole Richie from their reality TV show The Simple Life.
The pair wore blonde wigs and denim to recreate the show’s 2003 poster, before mimicking a scene from the TV show where the duo were called ‘dumb’ by someone working alongside them on the farm.
Richie reposted the video on his Instagram story, writing the word “obsessed” while US socialite Hilton said “iconic”.
Hilton opted for the outfit worn by Britney Spears in her 1998 debut single Baby One More Time, wearing a tied white shirt, gray cardigan, pleated skirt and hairdo in ponytails.
She shared multiple photos posing in the costume next to pink school lockers and in a classroom, writing on Instagram: “This is Britney the bitch. I love you icon @BritneySpears”
It also paid tribute to Little Mix singer Perrie Edwards, who transformed into fellow pop star Lady Gaga as she dressed her son Axel to look like Bruno Mars, following their new joint hit song Die With A Smile.
Her former bandmate Jade Thirlwall stepped up to dress up Little Bo Peep in a Toy Game inspired outfit, along with her friend Jordan Stevens from Rizzle Kicks, who donned a Mr Potato Head costume.
“Toy Gory: Little Hoe Peep edition,” the singer captioned photos on Instagram that showed a gruesome caricature of Woody from the film.
The pair were pictured arriving at Love Island host Maya Jama’s annual star-studded Halloween party, who kept up her high costume standard by creating a special Beetlejuice outfit.
Instead of donning the heroine’s classic black and white striped suit, she modernized it in a off-the-shoulder blazer dress, paired with matching stockings and black high heels.
To complete the look, she wore a glowing green curly wig to portray the hair of the character that actor Michael Keaton recently reprized in the 2024 Beetlejuice sequel.
“Beetlejuice’s unruly niece,” she captioned photos on Instagram.
Singer-songwriter Ed Sheeran had fun with his costume by dressing up as a viral meme of himself wearing a fluffy brown monkey bodysuit.
He shared a photo of him leaning over a table while holding a phone showing a photo of himself in a similar look, writing: “Haters gonna say its AI #halloweenbruv #feltcutemightdeletelater.”
YouTubers Amelia Dimoldenberg and Myleene Klass also celebrated the spooky time of year.
Klass, who rose to fame with the band Hear’Say, opted for a classic version of the Wonder Woman outfit, complete with long boots and a bodysuit in blue, red and gold.
While Diemoldenberg completely changed her look to Administrator Roz from Pixar’s Monsters Inc.
She shared a series of photos of the makeover look on Instagram, in which her hair was pulled up into a purple spike and the dress resembled the body of a slug-like monster.