Do Not Behave launches The Ultimate Monster Costume, a spoof Halloween shop selling a white T-shirt, jeans and white trainers

Key Takeaways

• Do Not Behave, the independent UK creative studio launched by Jo Moore in 2025, made The Ultimate Monster Costume with educators What Makes A Man? and Cheer Up Luv.

• The social campaign looked like a retail ad for an online Halloween costume store, published under the spoof shop name Ultimate Monsters.

• The Real Life Monster Costume is a white T-shirt, jeans and white trainers with no price, and its listed features are abusive behaviours towards women.

• The spoof website asks men to act as allies during the Halloween season, and Do Not Behave says it has received over 2.5k visits.

Do Not Behave has launched The Ultimate Monster Costume, a Halloween campaign that looks like an ordinary ad for an online costume store and clicks through to a spoof shop, where the most frightening outfit of the season turns out to be a white T-shirt, a pair of jeans and white trainers. The shop trades as Ultimate Monsters, and it has been built to raise awareness of violence against women and girls by showing that perpetrators are hard to spot because they look like everyday guys. This is a tactical social campaign made with the educators What Makes A Man? and Cheer Up Luv, its aim is to ask male allies to be more vigilant.

Do Not Behave's Ultimate Monsters shop lists a Real Life Monster Costume with five abusive behaviours as features

The Ultimate Monster Costume begins as seasonal retail advertising, published through an Instagram account called Ultimate Monsters and styled to resemble the promotions of an online Halloween costume store. Anyone who clicks through reaches a product page for the Real Life Monster Costume, which shows the intentionally average outfit of white T-shirt, jeans and white trainers. There is no price and nothing to add to a basket, however, because the only purchasing advice on offer is the instruction "Don't buy this disguise".

Part of the page where a shopper would expect fabric details and sizing instead sets out what the wearer does. The five listed features are "Invading women's personal space", "Not taking no for an answer", "Sharing nudes without consent", "Visiting chatrooms for tips on drugging" and "Committing sexual violence", so the list runs from everyday intrusion to outright assault. Beneath them, the section that would usually itemise the contents of the packet says the costume includes "Friend", "Classmate", "Boyfriend", "Colleague" and "Husband", which removes the comforting idea that this outfit belongs to a stranger in a dark alley.

The page then turns from the costume to the visitor with the lines "Real monsters don't look like monsters." and "Real allies don't let them hide." Visitors who press the "I'm on it" button are thanked and reminded that clicking was step one and that step two is up to them, while a further link invites them to share the costume through an Instagram reel. Do Not Behave has given a measure of take-up from the campaign, saying that the spoof site has received over 2.5k visits.

Do Not Behave's Monster Costume cites research where 94% of men believe they have a role in reducing sexual violence against women but only 29% have intervened

The figure printed on the spoof site explains why the campaign addresses men who would never recognise themselves in the features list, because it says that 94% of men believe they have a role in reducing sexual violence against women while only 29% report ever intervening. The site credits those numbers to Police Scotland and describes them as UK men, although they come from a survey of 250 men aged 18 to 35 in Scotland, carried out in September 2025 and published in November. The same survey found that 67% agreed seeing more men speak out would make them more confident in doing so, which is the gap the request for allies is addressing. Police Scotland has been making a similar appeal since October 2021 through its That Guy campaign, whose 2021 video linked sexual banter and harassment to sexual violence, and The Ultimate Monster Costume approaches the same subject through a shop window.

The wider backdrop is a problem that senior police chief Maggie Blyth described in July 2024 with the words "Violence against women and girls is a national emergency", in comments accompanying a study which estimated that at least one in 12 women in England and Wales becomes a victim each year. That study also put the number of perpetrators at 2.3 million adults annually, which is one in 20, and those numbers make it difficult to go on picturing a rare and recognisable type of man.

Both partners bring long experience of this subject to the campaign, and the spoof site credits them both by name. Cheer Up Luv began as a photo series by Eliza Hatch, which was already pairing portraits of women with their first person accounts of street harassment in July 2017, and it has since grown into a UK-based platform with a social audience of 220K+ across Instagram and TikTok. What Makes A Man Ltd was founded in 2024 by Andrew Bernard, known as Bernie, after 18 years delivering enterprise and careers education, and his work now covers workshops for students and teachers as well as bystander training for businesses and sports clubs.

Do Not Behave itself launched in July 2025 as a London studio and a 50/50 collaboration between Moore, formerly executive creative director at House 337, and The Behavioural Architects and remains a standalone business. Its name is inspired by behavioural science and aims to confront status quo bias, and at launch Moore said, "We want to embrace all the chaos in the industry at the moment as we believe it represents an opportunity to work differently with like-minded clients and deliver exciting and effective work."

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