Russell Brand steps into the tub of the beloved billionaire 'Arthur' in an all-new remake of the 1981 fan favorite starring Dudley Moore, and we've got the hubby-to-be of Katy Perry in his skivvies!

Russell says he's not in the least bit wary about making a remake of the beloved original, telling ET's Mark Steines, "It's not daunting. It's very, very exciting. I love Dudley Moore. I'm from the same place as Dudley Moore. I love English comedy. … I love him dearly, and so I feel very, very honored."

In theaters next year, 'Arthur' finds Russell in the title role as a man who likes a good drink or three and takes full advantage of his limitless riches with a lavish, playful lifestyle. But when his fortune is at stake and he's forced to choose between an arranged marriage with Susan (Jennifer Garner) and an uncertain future with Naomi (Greta Gerwig), who proves to be the love of his life, Arthur must finally decide what is most important in life.

"I've been poor and I've lived without love, and now I have some money and I have love, and the most important thing is love," says Russell. "If you focus on money, you're finished."

Greta takes on Liza Minnelli's role from the original, and she knows why Russell's famous fiancée finds him so irresistible! "He's so in love with Katy Perry -- I think that there's a combination of, like, reformed bad boy, really smart and funny, and knows his way around a hair brush. It's, like, lethal!"

Helen Mirren plays Arthur's lifelong nanny Hobson in the film, and asked if she likes seeing him run around the set in his briefs, the Oscar winner laughs and replies, "I know, I get sucked into these things... He is rather gorgeous, so yes, I'll have plenty more of that, hopefully."

And of that comical bathtub scene between Arthur and Hobson in the new movie, Russell jokes, "Ever since I met Dame Helen Mirren on a film called '[The] Tempest,' which is coming out soon... I wanted her to give me a bath. So I find her attractive, in a confusing way. I thought that the ultimate realization of the attractiveness that Dame Helen has would be for her to give me a bath."

Watch ET for more with the stars of 'Arthur'!