Getting into Hellboy costume was hell for David Harbour

How does one play a monster?

Let David Harbour, the new Hellboy, explain.

"You put on this suit, you put on an entire mask, horns, hair, eyes, teeth, a big red claw hand, a tail, and you look in the mirror, and it is just not you any more.

"It is another creature. It is almost like a rhinoceros or something. So to be able to play that, I can't just do what I normally do, which is explore human behaviour. I have to explore almost something bigger.

"So what I did is I went back to the comic books a lot," said the 43-year-old American actor known for playing heroic police chief Jim Hopper in the Netflix sci-fi horror series Stranger Things.

Harbour is talking about the reboot of Hellboy, which opens here tomorrow, in which he plays the titular half-demon.

It is the third film in the franchise based on a Dark Horse Comics graphic novel series by Mike Mignola, and features a new cast and director.

The first two, in 2004 and 2008, were written and directed by Guillermo del Toro, but when he was offered only a producer credit on the third, he dropped out and so did star Ron Perlman.

In the latest story, Hellboy is sent to England by his adoptive father (Ian McShane) who runs the Bureau for Paranormal Research and Defence to battle a trio of giants. He comes across the Blood Queen Nimue (Milla Jovovich), a resurrected sorceress thirsting for revenge who almost manages to seduce Hellboy over to the dark side.

Harbour said the producers, Mignola and director Neil Marshall just called him and offered him the part.

"They all watched Stranger Things Season 1 and were like, 'That is the guy we want to play Hellboy.'"

He added with a laugh: "I was like, 'Oh, that is flattering - and horrifying - that you guys would think that I would be this angry demon.'"

He admitted finding it "daunting and intimidating" to step into Perlman's shoes.

"When they approached me with it, I was like, 'Why? Are we sure we want to do this?' And then they pitched me a violent, horror-based, gory, scary version of Hellboy, which is different from what Guillermo and Ron did. And also, a younger, more identity problem-based Hellboy. I think Hellboy is bigger than both me and Ron.

"I hope after me, Hellboy has another life where another actor takes on the mantle."

The make-up and costume was quite an ordeal.

It took three hours to get on the whole rig and three people to help get it on, including the creature's designer Joel Harlow.

"So Joel would sit me down in the chair, we'd put on a skullcap for my hair, I would shave completely so there was no hair, because they were glueing your face, so it was like a waxing if you took it off again. They put on a headpiece hair thing and then they put on the elfin devil ears. They have little points to them, I love those things, like Spock."

The latex mask would take an hour. Then the suit went on after he was greased down. Up next were the horns, sideburns, beard and teeth.

He said: "And then the lens tech would come over and put in the eyes, these really large yellow contacts that extended beyond my eyes. They were hard to see in, which was not great for action stuff. I would get hit in the face occasionally.

"And then we'd strap on the tail and we'd put on the fists."

The suit got so hot he felt like he was going to pass out sometimes. Then the costume people would have to unzip it and put in air tubes to cool him off.

"The sweat on my face had nowhere to go. The horns had little spaces around them, it was so disgusting, but like toothpaste, you would kind of move it up your face and then they would pour out of the horns."

There were 65 such days of shooting.

"At one point, I walked in and said, 'I can't do it any more.' I had a little bit of a breakdown and they sat me down and said, 'You can do it.'

"And I was like, 'Okay, let's go.' It was like, how do you cross the Himalayas? Like the Dalai Lama said, one step at a time."

Harbour had to go to the gym as well to build up his body.

He said: "It was awful. I did a lot of training with a great trainer who works with my complaining. I don't like it. I much prefer sitting on my couch eating doughnuts, watching movies."

Next up for Harbour, aside from Season 3 of Stranger Things, is Black Widow, the standalone movie from the Marvel Cinematic Universe starring Scarlett Johansson, which starts shooting in June.

He is "really excited" about it.

"I know the general story, which I can't tell anyone because they will kick me out of the movie before we even start. I haven't read a full script yet, but the character seems great."

The writer is the president of the Hollywood Foreign Press Association, a non-profit organisation of entertainment journalists that also organises the annual Golden Globe Awards.