The German supermodel has revealed she dressed up as a wrinkly old woman for Halloween because she wanted to prove to people she is still in her prime.
The mother-of-four told People.com: "There was so much talk about me turning 40 this year and what it felt like to be older. I thought, really? I will show you old!"
Heidi enlisted the help of Oscar-winning makeup artist Bill Corso for her geriatric transformation, whom she asked to make a cast of her face.
She said: "The rest of my ideas - the grey hair, yellow-stained teeth, lots of wrinkles, a hunchback, arthritic hands, age spots and milky eyes - he just made happen!"
The blonde beauty, who has previously dressed up as Cleopatra and a Hindu goddess, completed her costume with pear necklace and a vintage designer suit, because, "you can never go wrong with Chanel, no matter how old you are."
Heidi, who celebrated her 40th birthday in June, hosted her 14th annual bash to celebrate the spooky holiday on Thursday night at the Marquee nightclub in New York City.