There's not, at first glance, much that seems terribly beastly about Dan Stevens, After all, the blond-haired, blue-eyed actor made his name as the perfectly domesticated Matthew Crawley in Downton Abbey - all silver spoons and cummerbunds and polite-but-earnest love.
But the producers of this year's biggest family film release, Disney's live-action remake of the much-loved 1991 classic Beauty and the Beast, must have seen a wilder side in the 34-year-old actor when they cast him to play the lonely monster who lives in an enchanted castle. Of course, beneath that heavy pelt and those fearsome teeth lies (spoiler alert!) a handsome prince just waiting to be unleashed by true love's kiss. But as any fairytale hero worth his salt will know, the character's animal persona is indivisible from his romantic appeal.
Perhaps that's why Stevens, who was always immaculately clean-shaven as Matthew Crawley on Downton, is sporting an off-duty beard for the press tour of the film. It is the day after the film's premiere in London's Leicester Square and Stevens and his co-stars wear the easy confidence of a team which knows beyond doubt it has a smash-hit on its hands.
For Emma Watson, who co-stars, it marks the moment when she is untethered in the popular imagination from Hermione Granger in Harry Potter, and becomes, for a whole generation of schoolchildren, the definitive Belle.
Stevens, who has two daughters and a son with his wife, the South-African jazz singer Susie Stevens, admits he's become much more familiar with Watson's Harry Potter back catalogue now "that I have kids myself".
"When we filmed this my eldest daughter was not aware of Harry Potter at all," he says. "And for her I think (Emma) is first and foremost Belle, which I think is wonderful."
She was very excited... most especially, he says, about Belle's iconic yellow ballgown, which was painstakingly recreated for the film.
"Emma came over to dinner one night when we were in pre-production... and it (the dress) was a hot topic of conversation for a lot of the shoot and it's, you know, a very important thing to get right. And over dinner we were talking about it and my daughter, who is five, was listening into the conversation and she hurried off next door with a pen and paper and then she came back and presented Emma with about five different dress designs that she had come up with next door. And Emma very sweetly sat and discussed some of the designs. A few weeks later my daughter came on set and saw Emma in the dress. And she was pretty convinced that it was her design that made it through."
As part of the generation which grew up with the 1991 Beauty and the Beast cartoon, Dan and Emma both felt huge responsibility "to our own childhood selves. How much we loved this thing..." he says. "But also I think Emma and I are interested in fairy tale and in story, and the chance to recreate this fairy tale, to tell it again, and to carry forward some of the great messages in it...
"It is a classic because it has such huge, not just one theme but actually a few very, very big themes that are always relevant, always pertinent. That was the challenge really - what torch are we carrying forward here?"
His contribution to that goal was creating a beast which is a more three-dimensional, rounded character. The complicated CGI wizardry which turns a suave British actor into a snarling, frightening-looking monster remains a mystery to most of us. But despite having to work with effects, Stevens was determined to bring his own signature to the character, fleshing out the Beast in a way that builds on and further develops the cartoon.
"The humour that you find in the animated feature - how does that translate when it becomes a real creature and you can't rely on cartoon tactics... we gave him more of a dry, educated wit," he says of the Beast, who in this version is damaged but loveable - a Shakespeare fan who lost his mother as a child and was emotionally neglected by his father, and whose literary spirit impresses Belle. "And we really looked at the kind of obstacles that Belle would have run up against... What kind of chauvinism and sexism and prejudice can the Beast exhibit that Belle has to batter through, but also what are his lovely, sweet, lovable qualities that she sees inside with her super-perception."
On paper, Stevens seems to slot pretty neatly into the current generation of young, male privileged and privately-educated actors who have infiltrated Hollywood; a group which includes Benedict Cumberbatch, Tom Hiddleston and Eddie Redmayne. He studied at Cambridge, and attended a prestigious private boarding school. But he has always insisted he's not posh - his background is rather more complicated.
He was raised by two teachers who adopted him at birth, along with his younger brother who was adopted from a different family. He was a scholarship kid at Tonbridge School in Kent and has said in the past that he never really fitted in there.
These days, he lives in New York with his wife, daughters and son. He married relatively young (while still in his 20s) and was perhaps particularly attuned to the resoundingly feminist message of Beauty and the Beast as the father of a little girl.
As Emma Watson says of Belle: "She was based on Katherine Hepburn, she was written by a woman. She was meant to be a departure. She was supposed to be a Disney princess gone rogue." There were, Watson says, "certain things that I had to safeguard".
For Stevens, performing in an all-singing all-dancing musical has also been a revelation. "The realisation in that musical theatre education is that song is an extension of our emotions.
"It's that thing that we can't necessarily express in words... what's so wonderful about musical theatre is that it's not just, here's a song, here's some words. It's what you get from that blending of the two.
Beauty and the Beast is released nationwide on Friday