02/22/2012 01:59 pm ET Updated Feb 24, 2012

Katy Perry Heads To 'Raising Hope,' Ashley Tisdale Lands Louis CK's CBS Comedy And More Casting News

Pop superstar Katy Perry is coming to Fox's "Raising Hope" for a guest starring role slated to air on Tues., Mar. 6 at 9:30 EST on Fox.

In the episode, entitled "Single White Female Role Model," Perry will play Rikki, a prison attendant who claims to be a friend from Sabrina's (Shannon Woodward) past.

“Shannon Woodward is my best friend,” said Perry in an official statement from Fox. “A couple weeks ago, I was home, just toasting up a frozen chicken fillet when she called me up and asked if I wanted to do something 'fun' for a change ... I thought, 'Sure, I have nothing else to do, and I like chillin' with my best friend.' ... I hope [creator Greg Garcia] is not secretly sabotaging my potential future career by type-casting me in the role of just a looker, so that I would never be able to play anything more challenging."

Meanwhile, former Disney starlet Ashley Tisdale is distancing herself from the the House of Mouse that made her famous -- and landed her a few famous BFFs. Tisdale is heading to Louis CK's untitled CBS multi-camera comedy, which centers on young creatives trying to make it in dire financial times. The pilot, written by Louis CK and Spike Feresten, is actually an update of a script that they cowrote 13 years ago. Tisdale will play Petra, a "beautiful and sarcastic assistant to a vintage clothing designer," according to TV Line, who confirmed the news.

In other casting news ...

Dennis Quaid and Michael Chiklis are in talks for lead roles in CBS' cowboy drama based on Ralph Lamb, a rodeo cowboy turned Las Vegas sheriff. Quaid would reportedly play Lamb, while Chiklis would star as a Chicago mob boss. [The Hollywood Reporter]

"Heroes" alum Milo Ventimiglia has signed on to star in Frank Darabont's new TNT drama pilot "L.A. Noir." Ventimiglia will play Ned Stax, a young former marine who served with Joe Teague during World War II. In the pilot, Stax is a lawyer being groomed to be a fixer for the mob. [TV Guide]

"Modern Family's" ditzy teen queen Haley Dunphy (Sarah Hyland) is getting a new boyfriend. Hyland's real-life boyfriend, Matt Prokop, has just been cast as Haley's latest love interest. [Zap2it]

"United States of Tara" star Brie Larson has landed the female lead in Nick Stoller's CBS pilot. In the comedy, a twentysomething guy (Michael Angarano) gets his heart broken by his girlfriend (Larson), only to wind up working one cubicle away from her at an ad agency. [TV Guide]

Former "Big Love" star Jeanne Tripplehorn has booked a two-episode arc on the Fox comedy "New Girl," which stars the adorkable Zooey Deschanel. Tripplehorn will play Russell's (Dermot Mulroney) ex-wife Ouli (Tripplehorn), who has a chilly reception to the new girl in his life -- Jess (Deschanel). [The Hollywood Reporter]

"Brothers & Sisters" star Ken Olin has been tapped to co-star in ABC's drama pilot "Americana." Olin will play Martin, the owner of a garment manufacturing company whose daughter designs clothes for the company. [The Hollywood Reporter]