Extreme body transformation helps David Harbour find his Santa in Violent Night

David Harbour finds physical transformations useful in getting inside the head of the characters he plays – including a Santa Claus like you’ve never seen before in Violent Night.

David Harbour has legions of fans around the world thanks to his role as plucky Chief of Police Jim Hopper in Stranger Things – but right now, his doctor isn’t one of them.

The reason his medico is mad is the US actor’s penchant for extreme body changes in recent years. Harbour rocked a dad bod as the out-of-shape, past-his prime USSR super-soldier Alexei Shostakov – aka the Red Guardian – in the 2021 Marvel hit, Black Widow, ballooning up to nearly 130kg, and then lost 30kg of it over the course of filming to also portray a younger version of the character.

He then dropped to about 85kg to play the lean, starving version of Hopper who was wasting away in a Russian prison at the beginning of the fourth season of Stranger Things, before stacking it all on again to play Santa Claus in his new movie, Violent Night.

“My doctor is very mad at me, and he says that every time I go in,” says Harbour over Zoom call from Budapest, where he is filming a movie adaptation of the beloved video game Gran Turismo.

David Harbour as Jim Hopper in Stranger Things. Picture: Netflix

“But you know, there are people that BASE jump too. So there are things that you love and you do that your doctor tells you shouldn’t do – and this is one of those things. It is hard on the body, and I’m going to have to get a little better at doing it using prosthetics and things like that.”

But as much as he might disappoint his doctor, Harbour says he finds the physical transformations useful in also getting inside the head of the characters he plays.

“Food affects our mood and our mind so much,” he says. “So there is something when you are really hungry that affects your psyche, and there is something when you are very, very sated and eating whatever you want that affects your psyche as well. I always like those things when I am creating characters.”

Given the number of Santa Claus portrayals committed to celluloid over the years, it’s fair to say that audiences won’t have seen one quite like Harbour’s in the appropriately titled Violent Night, which feels like a mash-up for John Wick, Die Hard and Home Alone, with a dash of Miracle on 34th Street thrown in for good measure.

“That was exactly the pitch – exactly what you said,” Harbour agrees with a laugh, adding that he didn’t quite know what to make of the concept when he was first approached.

It was only when he spoke to director Tommy Wirkola and producer David Leitch – the master of mayhem behind John Wick, Atomic Blonde, Deadpool 2 and Bullet Train – that he began to get his head around it.

John Leguizamo, David Harbour and director Tommy Wirkola represent Violent Night at New York Comic Con last month. Picture: Slaven Vlasic/Getty Images for Universal Pictures

This Santa, who looks like the iconic, red-suited, bearded figure of from shopping malls and catalogues, right down to the ‘ho-ho-ho’, is in fact a reformed ancient warrior, who once upon a time smote his foes with a mighty hammer called Skullcrusher.

Centuries of delivering presents to ungrateful, materialistic children have left him feeling bitter, trapped and rather more partial to the booze than is healthy, but when a group of mercenaries attack the estate of a filthy-rich family on Christmas Eve, Santa steps up to save the day. Bloody mayhem ensues as he rediscovers his both his fighting and Christmas spirit.

“I knew the action would be incredible,” Harbour says. “And then they sent me the script and I found that it has this funny, outrageous feel to it. Blood, action and madness, but then when I got to the end of the script I started to get a little choked up because it feels like a Christmas movie, and you come out believing in the spirit of Christmas as you go on the journey of the relationship between him and the little girl.”

David Harbour in Violent Night, directed by Tommy Wirkola.

Harbour had done plenty of fight and stunt work on previous action films, including Hellboy, and his stint as Red Guardian had given him experience in complex choreography while wearing a bulky suit, but he says the combat team assembled by former stuntman Leitch was “another level”. Harbour trained in jiu-jitsu and Graeco-Roman wrestling for three hours a day for two months, leaving him feeling more tired than he ever had been before.

“You see those sequences in John Wick or Atomic Blonde – they even did the new Matrix movie – they are the top guys and they have a training regimen that’s very generous in that they really want you as an actor to do as much as you can,” he says.

“Because when you are shooting choreo, it’s nice to shoot someone’s face and see them doing it. I remember going to see Atomic Blonde with Charlize Theron and watching these wide shots of her doing a bunch of stunts and being like ‘wow – that’s cool that it was her’.”

The fruits of Harbour’s labours are some bloody and brutal action scenes between Father Christmas and the crew of machinegun toting hired goons led by John Leguizamo’s Mr Scrooge. But pushing the physical limits of the actors sometimes came at a cost for their professional mentors.

“The great things about stunt guys and women is that they are insane and they have a discipline and an M.O. where they say ‘we are not allowed to hit you – but you are absolutely allowed to hit us’,” says Harbour with a laugh. “Not that I am trying but sometimes, in the heat of the moment, you will swing something around and bash some guy. They are always very sweet about it – and I did hit some guy in the helmet with this hammer pretty hard. He went down and I came over after the take and said ‘oh my God – I am so sorry’ and he just popped up and said ‘oh it’s fine’.”

Black Widow/Natasha Romanoff (Scarlett Johansson), Alexei (David Harbour) and Yelena (Florence Pugh) in Black Widow. Picture: Jay Maidment/Marvel Studios

Looming large on the horizon for Harbour is a return to the role of Red Guardian in Thunderbolts, which is due for release in 2024 as part of the MCU’s Phase 5. The action movie is shaping up at Marvel equivalent of DC’s Suicide Squad, assembling a team of “villains” from previous films and TV shows including Black Widow co-star Florence Pugh’s Yelena, Sebastian Stan as the Winter Soldier, Julia Louis-Dreyfus as Valentina Allegra de Fontaine, and Wyatt Russell as John Walker.

“I really like the ideas behind Thunderbolts that have been pitched to me,” says Harbour. “I think it’s going to be an incredibly fun, weird movie for the MCU, and I am just dying to dive back into that world. I also feel like there’s so much unexplored with Alexei and who he has become after he gets broken out of prison. There’s a lot of layers there and I can’t wait to dig in.”

Violent Night is in cinemas on Thursday