Were you an obsessive fan of anything as a kid?
‘“Thundercats” – if I hear the theme music I get nostalgic. And Dennis the Menace. I was a member of the Dennis the Menace fan club, which meant that you got a Gnasher badge.’
Which of the cast is most obsessed with Harry Potter?
‘Ezra Miller. There’s no question. He understands it on so many levels. He could write a dissertation on it.’
Did you ever need him to explain anything during filming?
‘In the first film, Samantha Morton’s character says “Are you a seeker? A seeker after truth?” and Newt’s line is “No, I’m more of a chaser, really.” And Ezra was like, “Dude, you have the greatest line.” I was like, “Oh yeah, yeah, yeah… why?” And then I was like, “Oh my God, the quidditch reference!” I hadn’t realised that was the whole thing. It took Ezra to point it out to me, embarrassingly.’
Were there any funny moments?
‘There was one moment in which I tried to get Katherine and Dan [Fogler] to do the hokey cokey. And it transpires that in America it’s called the “hokey pokey”, which I think sounds a bit sexual and dirty… They laughed me off the set for thinking it was the “hokey cokey”.’
What’s it like filming green-screen scenes?
‘All the poor stunt guys are always covered up in green morph suits, zipped over their faces – they look like green sperms. And for all the Warner Brothers “Fantastic Beasts” budget, there’s a scene in which we have to walk down some stairs to the banks of the Seine and they couldn’t afford the stairs. So there’s a really serious moment where me, Dan and Katherine are like, “We have to walk fast” and… [mimes walking down a staircase]. I think it’s been cut because I was so bad at it.’
If you were given an invisibility cloak, where would you go?
‘The Raphael Cartoons room at the V&A. I love the V&A. It’s a proper old-school museum: you can get seriously lost in it. In fact, I did get lost in it the other day.’
Which is your favourite beast?
‘Pickett, for loyalty, but a baby niffler for cuteness on steroids.’
What would your own fantastic beast look like?
‘When I did the Potter Patronus [advanced magic] thing I was a basset hound. I was so excited because I’d forgotten how much I love basset hounds. So I think it would be Dumbo-esque but of the basset hound variety, with massive long floppy ears and maybe it would just have a startling singing voice.’
Any weird fan interactions?
‘Seeing people dressed up. There was one extraordinary Pickett.’
If you had a suitcase like Newt’s, where would it take you to?