Damian Haas and Tiffany Thornton

The characters on Disney Channel's So Random! might have migrated from Sonny With a Chance, but star Tiffany Thornton says to expect a brand new show.

"You see me as Tawny when I say hello and goodnight but, other than that, you see us as different characters with different wigs doing different sketches and accents," she tells TVGuide.com.

See photos of Tiffany Thornton

After Demi Lovato announced she was exiting Sonny With a Chance in order to continue her recovery from an eating disorder, the channel announced they would spin-off the series to focus on Sonny's show-within-a-show. The result is a Saturday Night Live-type sketch show aimed at a younger audience. Luckily for Thornton, being funny is what she loves. "Physical comedy is right up my alley. I have so many friends that are good at crying on camera, but I would rather make people laugh," she says.

VIDEO: Tiffany Thornton loves Demi Lovato like a sister

Throughout the season, the show will feature musical guests such as Selena Gomez, Greyson Chance and Mitchel Musso. (Watch him tell us about the guest-spot below.) But will Lovato ever return to reprise her role as Sonny Munroe?

"It would be awesome to have her, but I think she's moved on from this part of her life and from being on the channel. She's ready to focus on her music and see where that takes her," she says. Thornton, who is having Lovato as a bridesmaid in her upcoming wedding, adds, "Demi's one of my best friends so it's hard to not have her here every day, but I'm super proud of everything she's accomplished so far and for taking steps to get healthy. She's a really talented girl and she'll go far regardless."

So Random! debuts Sunday at 8:30/7:30c on Disney.