What do you call a fear of Santa Claus? Claus-tro-phobia. I can’t take credit for that corker – it’s from a SpongeBob SquarePants episode, and it’s also delivered by Alexann in the new HBO Max documentary, Santa Camp. Alexann is a kid who’s turned up to a church in Chicago to meet “Trans Santa”. Unfortunately, so have a handful of Proud Boys and other protesters, who hold “SAVE SANTA” signs while shouting that Trans Santa is “destroying America”.

“The Bible that I read says this is a sin,” says one guy, wearing Proud Boys merch. As the disembodied voice of Santa Camp director Nick Sweeney points out, “Santa’s not in the Bible.”

The protesters were drowned out by the carollers. “But after the event, and understanding the full extent of what happened, it made me realise that there really is a need out there for my visibility,” Trans Santa, or Levi, tells the Guardian now.

Santa Camp follows the journeys of three unconventional Santas in their quest to provide better representation in the red suit. Levi is one of them, who appears alongside his partner Heidi, a Dr Claus version of Mrs Claus. There’s also Fin, who was born with spina bifida and uses an iPad to communicate. And there’s Chris, a black man who received hate mail when he put up an inflatable black Santa in his front yard in Arkansas, spurring him on to don the suit for himself (and for his young daughter).

Much of the action in the documentary takes place at Santa Camp, a “school for Santa, Mrs Claus and the Elves” run by the New England Santa Academy and held at a forest-ringed conference centre in New Hampshire. Australian film-maker Sweeney stumbled across the camp online and was instantly attracted to the idea.

“I love documenting sub-cultures – I actually studied sociology at UNSW before moving to New York – and it looked so fun and ridiculous,” he tells Guardian Australia. “Santas sleeping in bunk beds, and sitting around a campfire with professional elves and Mrs Clauses all sharing battle stories.”

Being a Santa is “big business”, he says; some of them make US$2,000 a night during the holidays. But at the camp, amid the PowerPoint presentations and “ho-ho-ho” coaching, he found the Santas were having increasingly urgent discussions about how they could diversify and how to respond to kids asking for toys that buck gender expectations. In a staff meeting, one (white male) Santa says, “We’d better get used to it, because as the last census bureau said, we are a minority now.”

At the camp, the majority of attenders still look like Grateful Dead and Eagles aficionados, with snowy white beards decades in the making. “Santa Claus is just an idea,” the camp’s founder, Dan Greenleaf, points out – and an idea hugely influenced by Coca-Cola at that. He’s keen to move with the times.

It’s into this environment of good intentions that the new Santas arrive. Fin, the Santa with spina bifida, arrives with his mother-stroke-“momager”, who sits in the car outside, worrying about how her son will fare. “Santa camps generally attract gentlemen of a certain age,” she says apprehensively. “Usually God-fearing Vietnam vet guys, Christian guys and … guys.”

Being the only black man present, Chris immediately feels lonely and awkward. He’s up against a lot of well-meaning white guys saying things like “kids don’t see colour” or asking how they should best talk to him as a black Santa. Later, at a storytelling session around a fire, he reads and then burns a racist letter he was sent. Many Santa onlookers cry.

At a folksy gathering of Mrs Clauses, who recommend holly-themed bonnets and festive xylophones that can be bought from Walmart, Heidi interrupts: “Excuse me, I’m Dr Claus, I’m not the wife.” She holds a PhD in counsellor education and supervision, and her dissertation dealt with trauma in trans high schoolers. A timid clapping and “bravo” echoes around the classroom, among some appalled looks. Actually, many of the Mrs Clauses are ripe for ignition; lately, many of them have been arguing for equal pay and billing. Dianne, for instance, has long been a doting Mrs Claus to her Santa husband, but has got pretty sick of being sidelined. “Mrs Claus is to Santa what a support act is to the Rolling Stones,” she says.

Things come to a head at an ice hockey game at which the couple is scheduled to appear. This year, Dianne has negotiated her own ice resurfacer on which to ride out into the rink.

“I’ve been quiet all these years and been the good little wife. Now it’s my turn – see how you like sitting at home,” she says, good-naturedly. Her Santa husband storms off. “We’re here to have a good time, not to piss Santa off,” he says. “Because Santa’s pissed off and you don’t want Santa pissed off. This shit of equal pay or equal rights … you earn your rights in this world.”

Levi and Heidi will reprise their roles for the fourth year this Christmas. They have collaborated on a children’s book, You Can Be a Claus Too: Lessons from Santa Camp, illustrating and writing it respectively.

“We have no interest in being ‘professional’ Clauses for pay,” Heidi says. “We only do volunteer events for LGBTQ+ youth in partnership with established community-based organisations.”

The reception to the documentary has brought them a flood of positive correspondence from around the world. “When we started doing this, I did it because Heidi asked me to,” Levi says. “But this event and everything we went through for this film really affirmed for me how important being a trans Santa can be.”

Sweeney wanted to make an uplifting film after a bleak 2020. Despite the tiffs and the darker presence of the protesters, he’s succeeded. Among many beautifully surreal moments, there are Santas kayaking and driving golf carts, and swimming in a lake so vast and dark that it looks like they’re floating in space.

“We all worry about getting things wrong, the stakes are high,” Sweeney says. “The awkward moments we see are actually very relatable. It’s how discussions around diversity and representation play out in the real world. Adapting to change isn’t easy or straightforward – it can be a bumpy sleigh ride.”

• Santa Camp is available to watch on Binge in Australia and on HBO Max in the US.