For the Tibetan Mastiffs living on Snow Mountain, a dog’s life has a simple riff; Guard a peaceful village of wool-making sheep from the wolves. To avoid distractions, leader Khampa (J.K. Simmons), forbids all music from the mountain. But when his son Body (Luke Wilson) discovers a radio dropped by a passing aeroplane, it takes just a few guitar licks for his fate to be sealed; Bodi wants to be a rock’n’roll star. Yet that means defying his father’s wishes, heading to the city and locating the legendary – and reclusive – musician Angus Scattergood (Eddie Izzard)…

In celebration of the UK release of Rock Dog, out from 16th June, we speak to Eddie Izzard about playing a feline rock’n’roll legend…

QUESTION: Do you have a certain affection for your character in Rock Dog?
EDDIE IZZARD: He’s fun. At the beginning, I wasn’t sure I wanted to do him. The fading rock star. Somewhere between fading and ageing – let’s put it that way. He’s not on the top of his game. He’s not coming up with anything creatively. And maybe he fired the band and only with the band could he come up with stuff. You think of some bands, working on individual projects, it doesn’t work. Collectively it works better.

QUESTION: Was there a specific musician you were thinking of?
EDDIE IZZARD: No, I went...having done Long John Silver with a London accent [in 2012 mini-series Treasure Island], when I played him, instead of doing the West Country accent, I thought, ‘I’ll go there first.’ And then I just started talking like him and it played well...and we kept it going. I’d say things like ‘Mother fudgecake’ – swearing for kids!

QUESTION: So nobody – say Mick Jagger – fed into your portrayal of Angus Scattergood?
EDDIE IZZARD: No, I think it was a merging of them all. I didn’t want to get stuck. The creative star who has got to a a comedy, I could be in a castle, but I’m not in a castle. So I could understand part of that mindset. What if the stuff won’t come anymore? I could understand that.

QUESTION: Does that worry you, slipping into a creative funk where you might dry up?
EDDIE IZZARD: No, it doesn’t! It is a scary thing to worry about and worrying about it might cause it to come. Because I road test my my new shows, I workshop it all in, so I should get there. Even if the first stuff I do isn’t funny, I keep going until I go, ‘That’s funny!’ It’s like verbal sculpture – each night, I’m sculpting away at the thing, having done a sculpture the night before. So in the end, you’re coming up with this fantastic sculpture every night and you know where to go with it. I’m just not worried about it. Maybe I should be!

QUESTION: At least with comedy, you can react off world events...
EDDIE IZZARD: But I don’t do the world stuff. I never do topical. It dies in the recording. You say, ‘God that Earthquake in Italy!’ And people go, ‘Was there one in Italy?’ I do ancient history. God, Richard III – what a bastard! He died in a car park. I do stuff so old, that it won’t actually ever get old.

QUESTION: You’ve done animation voiceovers before, like Cars 2 and The Simpsons. How was that?
EDDIE IZZARD: For The Simpsons, I said, ‘I don’t want to play myself in it.’ Quite often they get celebrities to play themselves. I said, ‘Can I play a character?’ But there are executive producers who run it, and then Matt Groening, and he said, ‘Do you want to do that’ I said, ‘Yes, I’d love to.’ It took a while to get into the mix. I actually played a guy who was a security expert selling them safety alarms, but then I threw in the voice of Prince Charles – if he sounded like James Mason! And a bit of the Queen! So I threw them in and they used them. Now it just looks like I played the Queen in it.

QUESTION: Did you always dream of doing The Simpsons?
EDDIE IZZARD: I’ve always loved The Simpsons. I wanted to make something like The Simpsons. What Hank Azaria and Harry Shearer do – they do five voices each. I’d love to do that. It’s a good use of my comedy in a film medium. Doing different voices, I love doing that. So if I could shove them all in there, silly voices, and say silly things, that would be great.

QUESTION: After the marathons of marathons that you did, did you get addicted to running?
EDDIE IZZARD: Not really. I see the logic of having a healthy body and lifestyle and I also noticed that all wild animals are fit, and if you don’t use it, it will punish you. A house that’s not lived in will begin to attack itself and will start to fall down. A car that’s not used will begin to attack itself and rust. And humans are the same. We have to use these units. They’re designed to hunt, to move fast, to have these abilities. Whatever you want – I’m not saying what – you could cycle fast, swim fast. The spurts of activity – this is what we’re supposed to do. There are big lions, big tigers – they don’t necessarily run about all the time, but at a certain point they think, ‘Let’s go and get some dinner.’ And they hare off. And they don’t go, ‘Ooh, I can’t, it’s the old leg.’

QUESTION: In the wild, if you were a wild animal, what would you be?
EDDIE IZZARD: No, I don’t think that way! In the wild, I’m just me. I’m trying to bring the wild to us. We’re natural animals. We consider ourselves refined, but in fact we’re natural animals, and that’s what we’ve lost.