Kat Dennings, the Funny Girl Who Wandered Into TV LOS ANGELES - Kat Dennings has been daydreaming about turning herself into a perturbed porcupine. Well, not literally. But if the "2 Broke Girls" actress had her way, she would wear a leather jacket covered in sharp metal spikes when she mingles with advertisers on Wednesday as part of CBS's upfront presentation. Upfronts, an annual show-and-tell for advertisers, are important to networks trying to sell their fall lineups. That being the case, one should be on one's best behavior. "But it's a mob, and some people grab you, or at least that's my experience," Ms. Dennings said. It's kind of overwhelming. If Ms. Dennings, 25, felt manhandled a year ago, when "2 Broke Girls" was just another laugh-track CBS sitcom awaiting its debut, she is right to worry about what awaits her this time around. The series, which stars Ms. Dennings and Beth Behrs as waitresses with R-rated mouths, overcame early complaints of racial stereotyping and crude humor to become the season's No. 1 new comedy. Original episodes of "2 Broke Girls" attracted an average of 13.4 million viewers through April 29, according to Nielsen. To compare, Fox's "New Girl" ranked second among new comedies, attracting about nine million viewers. The show is so popular that some media buyers think CBS will risk moving "2 Broke Girls" to the all-important Thursday night lineup, pairing it with "The Big Bang Theory" to form a must-see comedy block. CBS declined to comment ahead of its Wednesday scheduling announcement. Ms. Dennings has struck a chord on "2 Broke Girls" with her portrayal of Max, who has a murderous sideways glance and an offbeat, deadpan wit. Somewhere inside is a sweetheart, but it's buried under a bawdy sense of humor. Pity the ketchup bottle in a recent episode. "Kat is incredibly interesting because she's the ironic indie girl succeeding in a big, broad comedy," said Brent Poer, executive creative director at LiquidThread, a unit of Starcom MediaVest, the media buying agency. "You talk to the other networks, and they all say, "I wish I had that show," and Kat is a big reason why." Even so, casting such a young actress in an anchor role was a risky move for CBS, which tends to build comedies around established stars. But younger performers help draw the younger viewers that Madison Avenue pays a premium to reach: "2 Broke Girls" attracts the youngest audience of any CBS show except for "How I Met Your Mother." Broadcast television as a whole has been succeeding with what Hollywood refers to as "quirky girl" sitcoms - character actresses as leading ladies. Perhaps riding an entertainment pendulum shift started by the film "Bridesmaids," entries include Fox's "New Girl," which stars Zooey Deschanel, and ABC's "Don't Trust the B---- in Apartment 23," starring Krysten Ritter as an eccentric, manipulative roommate. The new shows that networks will unveil this week are stuffed with similar characters. One prominent pilot stars Mindy Kaling, known for "The Office," as an idiosyncratic gynecologist. You get the feeling from spending time with Ms. Dennings that she's not entirely comfortable with her breakout status. She calls herself "socially weird" and said that popping up at stylish restaurants or attending endless Hollywood parties would make her "vomitous." She lives in the low-key Studio City neighborhood here. "I think she just sits on her couch on the weekends, and that's one of the things that I love about her," said Michael Patrick King, the executive producer and co-creator of "2 Broke Girls." There's nothing manufactured about her, and that comes through on-screen. People are responding to her because it feels like an individual has wandered into their living room. Ms. Dennings, pretty with a playful touch of Goth style, points out that she has never followed the early advice casting agents gave her: tighten up your teeth, dye your hair, lose weight, get a tan. Unlike many actresses, Ms. Dennings does not pretend that "2 Broke Girls" is art, insisting that Max is little more than a heightened version of herself.