LOS ANGELES -- Now that Arnold Schwarzenegger has been lost to the world of politics, it's hard to imagine an ongoing Hollywood success story as remarkable as that of Dwayne "The Rock" Johnson. Beginning his career in the unlikeliest of places -- the wrestling ring -- Johnson has been able to overcome his muscle-bound stigma to become a star of action movies ("The Rundown"), family films ("Race to Witch Mountain") and comedies (his appearances on "Saturday Night Live" have yielded many instant-classic moments).

This weekend, he returns with "Tooth Fairy," a fun-loving family flick that casts the big man as a hockey player forced to wear wings and collect the incisors of small children. It's the type of silly flick Ah-nuld would have relished in his early-'90s "Junior" period and one that Johnson similarly hopes will expand his range.

Recently, we sat down to talk about tooth fairies, "Family Guy," his new muscles and everything else the Rock has cooking.

MTV: Dwayne, the image on the poster for "Tooth Fairy" says it all: "Come see the Rock in a tutu." But was there something more here that made you want to make this film?

Dwayne Johnson: Yeah, when this came across my desk, I wasn't gonna let it go. Sometimes scripts come across, and you're like, "You know, I could let that one go; maybe someone else could do it." But not this. It's special. A funny, funny, funny movie. And also, we had the great opportunity of creating [the first onscreen manifestation of] an iconic figure that's been around forever.

MTV: When you were a kid, did you believe in the tooth fairy?

Johnson: I still do believe in the tooth fairy; yeah, the fairy exists. I know generally, the tooth fairy was really good to me. When I was a kid, losing teeth, I'd get one, two or three dollars. The cool thing for me was that the tooth fairy always gave me paper money -- paper money is better than coins.

MTV: One of the best scenes in this movie has you encountering another fairy who is almost like a drug dealer -- a sketchy character played by Seth McFarlane. And recently, we saw you on "Family Guy."

Johnson: I love Seth. What was I doing on "Family Guy"?

MTV: You were using action figures to simulate sex between Peter and Lois; it was hilarious. How did these two crazy cameos come to pass?

Johnson: I've always been such a big fan of that show, for years. Seth came on for that cameo in "Tooth," we had a blast, and I said, "Any time you want me to come on and play, I'd love to." He was like, "Great!" They wrote that little scene we did, I came on and returned the favor. Seth is a great guy; I'm happy for him.

MTV: Would you ever want to collaborate with him further?

Johnson: Oh, I would love to. [I'm sure] it would be very blue. And it would involve action figures. He's a smart guy, which is why he's been so successful over the years.

MTV: We've interviewed you many times over the years, but you've never been as big as you are now. Have you been amping up your workouts for some purpose? For a role?

Johnson: Yes, I am preparing for an action role in a film called "Faster." It's myself and Billy Bob Thornton. You know, making people laugh, feeling good and entertaining them in movies is great -- but there is nothing like kickin' ass. I love that.

MTV: Why did you feel the need to get so much bigger for this? You look more muscular than even "Walking Tall" and "The Scorpion King."

Johnson: I've been heavier in the past, but I just haven't been [like this]. I've changed my training around. The training has been tweaked, the volume of it is just a bit more. Plus, when you get older, your muscles -- especially if you take care of yourself -- will mature nicely.

MTV: There are some very funny lines in the movie, and between yourself and Billy Crystal and Stephen Merchant, many seem improvised. Are there any gems that you can point to and say, "I came up with that!"

Johnson: [Flexes his biceps.] That's my gem. The "hammer brothers" line is funny. [In the movie he flexes and says] "If you ever wanna meet the hammer brothers, they're always in town: jack and sledge!"

Check out everything we've got on "The Tooth Fairy."

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