Rated-R movies come out all the time. But they rarely feature a pre-teen female assassin named Hit-Girl who swears like a sailor and kills without remorse. Clearly "Kick-Ass" ain't your average movie. And star Chloe Grace Moretz ain't your average actor.

The young Ms. Moretz isn't the main star of "Kick-Ass," but she's the one getting the most online attention. As the movie hits theaters, Web searches on "chloe moretz" are up an astonishing 3,423% in the past 24 hours. That places her in Yahoo!'s top 250 overall search terms, ahead of such search (and tabloid) mainstays as Lindsay Lohan and even Britney Spears. The word is out on Chloe.

But it's not just the searchers who are interested in learning more on the young actor. Critics are also applauding her work as "Hit-Girl," the purple-wigged crime fighter, who can move like she's in "The Matrix." Claudia Puig of USA Today calls the actor "terrific as the fearless and foul-mouthed 11-year-old Hit-Girl." Moretz's costar Aaron Johnson, who plays the title character, commented, "She blew it straight out of the park. I've never even seen adults pull off anything like this."

Ms. Moretz is modest when praised. Though she did nearly all her own stunts (after training with Jackie Chan's stunt team), the actor reminds viewers not to take the whole movie too seriously. For example: her controversial swearing. The 13-year-old says that if she talked like that in real life, she would be "grounded for years." And if she stays up too late on the computer, she'll "lose it for two months."

It's also worth noting that searches on "hit girl costume" are already beginning to climb. Many Web searchers are looking to get an early jump on their Halloween outfits. One person who won't be wearing one on October 31: Ms. Moretz. Since filming commenced, the actor hit a growth spurt and is now too tall for the outfit.

Just as well. If she wore the outfit, she might fall back into character and start swearing. And that would lead to some serious parental punishment.