He iS the biggest villain in the universe – and lives with his mum and dad, enjoys long walks and collects toy animals. Yes, the latest incarnation of Star Wars ultra-baddie Darth Vader is just a great big softie.

But in ten days actor Hayden Christensen will take his first steps along the road to becoming evil personified with the opening of the latest Star Wars movie, Episode II — Attack Of The Clones.

Blue-eyed blond Canadian hunk Hayden, 20, was not even born when Vader first sent shivers down the spines of cinema audiences in 1977. Now he is playing the lead role of Anakin Skywalker, the young Jedi knight who, as all Star Wars fans know, is eventually transformed into Vader. Yet off-screen Hayden is so squeaky clean it is hard to imagine anyone less acquainted with “the dark side”. After all, this is the man whose favourite movie is Disney’s cartoon version of Robin Hood.

The second-youngest of four children, Hayden still lives at the family home in the suburbs of Toronto. Dad David is a software programmer and mum Alie is a corporate speech-writer. He says: "I try to do everything to be a good son. I come home for dinner when I’m in town and keep out of trouble. My folks make me mow the grass and take out the garbage. I love my mother so much. I’m a momma’s boy. I still live in the same bedroom I’ve been in since I was five. I prefer to be with my family and the people I was brought up with. My bedroom has plain, grey walls with no posters. All my sports trophies are in my closet. I also have a toy frog collection. One was given to me when I was 12 and my sister thought it would be nice for another frog to keep it company. Then everyone started giving me frogs, some made of wood, some of nuts from the Amazon forest and some beanbag frogs."

Hayden was set on the road to an acting career when his grandmother in New York enrolled him in a theatrical studio in Manhattan during summer holidays. His first taste of showbiz came by chance at the age of eight. Hayden’s then 14-year-old sister landed a part in a Pringles crisps advert and went looking for an agent with her parents. He recalls: "I went along for the ride because there was no one to babysit me. All of a sudden they were asking me if I wanted to do a few commercials. I said, ‘Why not?’"

During his teens he started dabbling in high school theatre and had bit parts on TV and in the movies. In 1999, while playing a mopey teen on short-lived American drama Higher Ground, Hayden met Star Wars Episode II casting director Robin Gurland — and the next stage in his career was set in motion. Director George Lucas chose Hayden above Leonardo DiCaprio and 400 other hopefuls to play Vader — despite the young actor’s battle with his nerves. Hayden had been so jittery before his two auditions that he threw up on the plane before both meetings. And mid-way through his second reading, his voice "just went away for some reason." But Lucas was so struck by the sexual chemistry between Hayden and his screen lover Natalie Portman, who plays Queen Padme Amidala, that he hired him immediately.

The latest Star Wars instalment is tipped to beat Titanic as the biggest movie of all time when it goes on release in Britain and the US on May 16. Attack Of The Clones follows on from where 1999’s The Phantom Menace left off. It is the second of Lucas’s new trilogy which is a prequel to the original 1970s and 1980s releases.

In the film, Jedi knight Anakin is a student of mentor and friend Obi-Wan Kenobi, played by Ewan McGregor. But he goes on to fall in love with Amidala and by breaking his Jedi vow of chastity he enters the dark side — becoming Darth Vader.

Hayden says: “Working with Lucas was absolutely incredible, the best summer of my life. When Episode 1 came out, my entire high school went to the first showing. It was a big event and to be a part of that now is very special. I loved working with Ewan McGregor. He was always able to lighten up a situation. He’s such a strong actor so it’s inspiring to work with him. He really brings up the level of everyone else and makes it a very enjoyable experience."

And there were odd moments. Hayden reveals: “My pants split right up to my crotch numerous times. It happened over and over when I was doing jumps. So there was always something to laugh at, even if it was me. Making a Star Wars movie is the most pleasant experience you could ask for."

Yet Hayden is determined not to let global fame go to his head. He says: "I’m nervous about what’s going to happen to my life. It’s somewhat exciting but for the most part I’d like to keep it the way it is right now. I’m a little reclusive. I like nights to myself when I can decide what time I want to go to bed and not have it dictated by the people I’m hanging out with. I’m not looking for limousines, five-star hotels and bodyguards. I enjoy my privacy and love walking around different cities without being recognised. I only hope Star Wars won’t stop me doing that. I’m not totally afraid of the fame but I’m not going to embrace it with open arms. However, I signed on the dotted line for Star Wars and I can’t really blame anyone after that point."

Despite rumours of an off-screen romance with Natalie Portman, Hayden insists he is single and plans to stay that way for the moment. He says: "I don’t have a girlfriend right now and I’m not really looking for one either. "I don’t have the time. I’m not in one place for long enough so it’s not on the cards."