Heidi Klum Shares BTS Secrets About Her Most Iconic Halloween Costumes (Exclusive)

The supermodel is celebrating 20 years of ruling Halloween!

No one rules Halloween like Heidi Klum, and she knows it. 

ET exclusively sat down with Klum at the Prosthetic Artist's Studio in Englewood, New Jersey, to look back at her epic costumes, 20 years after she threw her first Halloween party in New York City. 

The supermodel, who has partnered with Amazon to give fans a unique look into her costume this year, remembered feeling disappointed by the lack of great Halloween parties in the city 20 years ago. 

"I kind of asked my friends and everyone like, 'Where do we go? What party is on tonight?' So we went to a few parties and I kind of thought, 'This is New York City -- this is the parties that they have?'" she recalls. "So I thought, 'I'm going to have to take that over and I'm going to make a party every night on Halloween and I'm going to show them how it's done.'"

Over the years, Klum has wowed in costumes like a human body, an ape, Jessica Rabbit and more. Some hold sweeter memories than others, with her 2013 costume as an old lady being her favorite. 

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"I loved it for myself to see what I'm going to look like, but also because I was turning 40 and people were always saying, 'Wow, you're already 40, you're really old now. When are you going to stop modeling? When are you going to stop doing what you're doing?'" the now-46-year-old says. "I'm like, '40 is not old, people! ... Like, I should just stay at home and not do anything anymore? I'm going to show you what's old or how I'm going to be old.' So, that's how I got that idea."

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Her 2001 Lady Godiva look is one she wishes she did a little differently. "My costume was not the best. Some of the makeup that I did wasn't as great and some of the costumes obviously because I didn't know these people at the time and I was kind of doing it by myself as good as I could," she explains. "As every year became bigger and the parties became bigger, and people were more interested in it, I kind of put my tentacles out more to find people who can help me make my vision become reality and make it more fantasy." 

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The mom of four now starts putting together her Halloween costume months in advance -- though some ideas never saw the light of day. "I had some ideas that maybe aren't as politically correct and nowadays you have to be so careful with what you do," she shares. "For example, Kali is an Indian goddess. I went to India many times. I love India. I love Indian people. I love their culture. For me, for example, it was more showing one of their goddess and by no means did I want to disrespect anybody and their religion. ... so yeah, some things have been vetoed because they were not that politically correct."

The model never has a "plan B." "I have to make it work because there's so much that goes into it and so many pieces are being built before ...If it wouldn't work out, I would probably stay in bed and pretend I'm sick. I probably wouldn't go. I could not have a costume that is not good," she jokes. 

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It takes hours to get into some of Klum's Halloween costumes, and hours to get out of them. "For example, when I was Jessica Rabbit... it took two hours to take all of that off, because it's very, very harsh glue that they put on your skin and then they have to put glue remover under it," she reveals. "I mean, I had a little bit here and there where my own skin would come off with it, but I'm always like, 'Be careful with my face.'"

Klum's Kali costume ended up leaving a "blue tint" on a white marble bathroom -- "I think I probably had to pay extra for cleaning service afterwards," she admits -- but she doesn't know "what I was thinking" when she committed to being a robot in 2010. 

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"I really wanted to be very tall and I was walking on stilts. I had to learn how to walk on stilts for a week and then again I did my own makeup and I had to match the suit again and put all that color on and then had sparkles. I mean, I had sparkles for days," she says. 

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Klum's worst wardrobe malfunction occurred in 2011, when she dressed as an ape. "I couldn't really go to the bathroom," she says with a laugh. "And I think we had to cut a hole in the bottom because it was a whole hairy suit. And then it was really hard to go to the bathroom with all that hair. It was very tricky."

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Years earlier, Klum found herself getting creative to hide her nearly nine-month baby bump. She ended up disguising it by dressing as Eve's apple. "I was pregnant with my third child, with Johan...  It needs to be big because I don't want to do any harm to the baby, could be a pumpkin, I'm going to be an apple -- so then I was an apple. And it was perfect," she says. 

The problem then became getting to the party. "I couldn't fit in a car," she confesses. "We had to get a convertible so I could climb over the top into the car." 

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In 2016, Klum barely dressed up at all -- her costume was instead five models transformed into her "clones." "That was perfect. I loved it. I was just running around. I was making sure everyone was eating and I was like, 'Can I get you more coffees? I was just checking up on everyone. I love that a lot," she shares. 

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The next year, Klum went all out, dressing up as Michael Jackson's "Thriller." "I have to say, also one of my favorites. I mean, it was shocking how real it was, because it's not just a mask that you buy at those Halloween stores and you stick it on and it's just there," she says. "[It's] very trippy, especially when you have a few glasses of wine and you go to the bathroom and you're like, 'Oh my god.' And then you're always worried, 'Does it come off?'"

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Klum's now-husband, Tom Kaulitz, joined in on the fun last year, as they dressed as Shrek and Princess Fiona. They arrived in an onion buggie. 

"Who doesn't want to drive around in an onion buggie? It was so much fun, just my husband and I in this onion buggie. I mean, I couldn't stop laughing," she remembers. 

"I think anyone who is with me, they already have to deal with a lot, so I think Halloween is just an extra crazy add on," she jokes of convincing Kaulitz to do a couples costume. 

Of course, Klum isn't the only one dressing up at her annual Halloween party. It's also a chance for other celebs to shine. 

"I'm obviously very excited when celebrities come to my parties, but for me, I'm not so celebrity crazy that I'm like, 'Oh my gosh!'" she expresses. "I love a costume. It doesn't matter who does the costume, so I'm more intrigued by what people show up. I always tell all my friends, 'Outdo me. Try it, go for it!'"

"There are some people that do some pretty amazing costumes, or sometimes it's just the simplicity -- sometimes it's just the idea," she continues. "There was this one guy many, many years ago, he came as a mattress. It was, I don't know, it's just I've never seen anything like it. He literally took a king mattress and cut a piece out in the inside where he could slip in so you could just see his face. His arms were on the outside and he was just a gigantic mattress. He was hidden inside this mattress, it was genius!" 

This year, Klum is ready to let fans get a better look at her costume. 

"This year is my 20th anniversary of my Halloween party, so I thought it would be fun for people to watch live when I get ready," she shares. Klum ended up partnering with Amazon. 

"On the 34th Street store of Amazon, I'm gonna be sitting in the window and people can just come by all day long and just watch the process if they're interested in seeing something like that," she says. "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. ... [people] can hang out there all day and watch or come in the morning and then shop and come back in the afternoon. I'll still be there. Come and watch if you want!"

See more on Klum's epic Halloween looks in the video below. 

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