Transcript for The evolution of Halloween costumes have made it the sexiest holiday of the year
feminism or just too much. Give me some attitude. Reporter: It's the sexiest holiday of the year, but dressing up on Halloween has come a long way since because this is thriller Reporter: The costumes have become sexier, and sexy costumes have taken on a life of their own, morphing from classic looks like the S.W.A.T. Hottie and angel, to tongue-in-cheek and topical, like fake news. We get a lot of inspiration from, you know, girls in the office, they're drinking white claw. Reporter: These days nothing is off limits, even childhood friends like Mr. Rogers. Please won't you be my neighbor Reporter: Isn't Mr. Rogers sexy enough? He is, why not bring him to life a little more. Reporter: She is the vp of merchandising at yandy. Every year they generate thousands of costumes and tweets. Make sure you go out there wearing what you want. Sexy Mr. Rogers is just one that has gone viral already. You seem to do this every year. Do you laugh? You have a giggle at it. Reporter: Based on the headlines, it seems a lot of people had a giggle at that one. He's the nicest neighbor in town. I grew up with Mr. Rogers. To do this is an honor and a lighthearted costume. Reporter: Not everyone is laughing. The company has courted plenty of controversy, too. Last year, their sexy red maiden was pulled from shelves. Why pull that? It wasn't what we wanted our season to be focussed on. Again, this is a fun time. Let's not make it a darker time. Have fun. That's all this is. That's all Halloween is, a day to escape in and have a blast. Reporter: And, at yandy, it's clear they are having a blast. How much fun do you have coming up with these ideas? We always say this. If someone was listening to the conversations I'm having with the factory, like this crest does not look right. This is ridiculous. They're very, very kind of ridiculous kind of conversations, but very serious to us. First of all, this is a 365-day-a-year business for us. We're thinking of Halloween for a year. Reporter: A year. So November 1st you get started. Yep, we're always watching the news cycle. We're always kind of taking a look at what we could spin. We have a running dock in the office that is open to everybody to add ideas, everybody from warehouse to hr is always giving us ideas. Some of the husbands and wives at yandy are always giving us ideas. We pull from a pool I'd say. Reporter: Not every idea has what it takes to be a hit. What are some memorable ones that ended up on the cutting floor. We had Elizabeth Holmes. Fat Thor. You could probably pull that one off at home. Wig, red lipstick and a dress. Reporter: It's a never-ending while we visited offices in Phoenix, Arizona, just weeks before Halloween, kylie Jenner's rise and shine video went viral. The women at yandy went to work. This shall be the three pieces that we need to create the rise and shine. Reporter: Other recent adds to the 2019 collection include "Ms. Impeachment", and that sold-out chicken sandwich. Sometimes we're like straight to the drawing board. We are design costumes for women. The majority of us are women here, so we're having fun. It's a laugh. I mean, sexy Bob Ross, I think she had all the elements there to be sexy. We just made the shorts for his jeans really, really, really short and added the palette, and everything like that. I think we nailed it. Reporter: You taught me something about the Bob Ross costume. Thorts. When they're so short they could be a thong, they're thorts. Reporter: You can always go with actual thongs, like the Kardashians last year, dressed as Victoria's secret angels on their show. I would describe it as something that's been going on for at least 20 years but has gotten to the extreme in the last five. Used to be just the people at the party would see the outfit, now you're posting it to thousands of followers. Halloween is the one day a year where a girl can dress like a total slut and nobody can say anything about it. I'm a mouse, Duh. Reporter: And "Sex in the city." Witch and sexy kitten. Reporter: And beloved by millions. Those who argue it's feminist and those who say it's not. A true feminist just does what see wants to do. I think people should embrace it and have fun. Reporter: Believe it or not, there's even a study on the subject. Professors from west Chester university have followed the phenomenon closely. What made you want to study Halloween costumes? You can see some of the most potent examples of gender roles when you look at holidays. I've had students say are you aware what's going on in adult costumes? Part of the interest was there. Reporter: The professors and students studied 1600 costumes and found over 90% of women's costumes were sexualized. I had semester go online and see how many costumes they had to look at before they could find a costume that wasn't sexualizing or objectifying. They had to go to 50, 120. For the boys, you looked at the first one. Reporter: You're saying this isn't about women wearing what they want, they're not given any other options. Sexual agency is powerful and empowering for many people, and I think it's really important for us to stop making appearance comments and shaming folks for the way that they dress. But the purpose of our research is not about restricting options. It's about expanding them. And I think also thinking about our definition of what sexy is. Reporter: Yandy offers plenty of objections that are more full coverage, with over 1,000 plus-sized options. One of the arguments we've heard are there aren't enough options for women who don't want to dress in a revealing manner. We're telling all the girls out there to own your sexy. Everything from floor length to ball gown to thorts, we've got you girl. I'm not comfortable in a thort. But many people are. Reporter: It's a moving market. We've done over 120,000 Halloween orders to date so far this year. These are safe for work costumes. This is a nice pumpkin tee shirt dress. Reporter: You can never have too many sexy tops apparently. No. Reporter: What are some of your most popular costumes? Our S.W.A.T. Hottie. Still need the tried and trues, S.W.A.T. Hotties, day after day. Reporter: What would the world do without S.W.A.T. Hotties. Day. All controversy aside, enjoy it. Reporter: Even the professors can't argue with that. I love Halloween. You and me both. It's my favorite. One of the things that's also happening is there are movements, I mean, I hear the word body positivity movement. That's empowering. If it's an opportunity to feel sexy, I think embracing that is awesome. Happy Halloween! Reporter: For "Nightline," I'm Diane Macedo in Phoenix.
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