is the latest pop girl gone wild. "I have a crazy tattoo: a little, itty-bitty heart on my toe," says Moore, who got the ink during a January tattoo-parlor trip with pal Jack Osbourne. "It looks like I was bored in class and doodled on my toe. That's my attempt at being a rebellious rock star. It didn't really work."
Okay, maybe Moore will never rule the tabloids. But the maturing singer-actress, 20, is still making her share of surprise—if more subtly subversive—moves. She tweaks her squeaky-clean image playing a less-than-angelic Christian fundamentalist teen in the new movie Saved!
, a satire set in an evangelical high school. Will the Catholic-raised Moore offend her religious fans? "If you can't laugh a little bit at things, then obviously this movie is not for you," she says. On the movie's Vancouver set, she rapped explicit Eminem tunes during karaoke nights and helped castmates pelt hotel passersby with marshmallows. Still, "Mandy has this inherent goodness to her," says costar Eva Amurri, "so that even when she's acting like a bitch from hell onscreen, it still shows through."
After playing nice in recent movies A Walk to Remember
, How to Deal
and Chasing Liberty
, Moore relished the chance to finally be a mean girl. "It's so much more fun to play these characters than the girl that gets the guy at the end of the film," she says, "because guys suck!" Her venting is understandable: She and tennis star Andy Roddick, 21, broke off their year-and-a-half romance in March. "Allowing yourself to be upset is important. I've indulged in more than a few cupcakes," says Moore, who's countering the calories with Pilates. Living solo in a one-bedroom New York City apartment as she films the musical comedy Romance & Cigarettes
has also helped her cope. "It used to be that I couldn't be by myself," she says, "and now I've come to savor it." So much, in fact, that Moore is considering moving out of the five-bedroom Los Feliz, Calif., pad she bought her family in 2002.
Next up: a return to the recording studio. "I have a lot to say, a lot to sing about," says Moore, who has already begun writing songs. "It feels like a fresh, clean start."