Joan Rivers
Comedian Joan Rivers arrives for the premiere of the documentary "Joan Rivers: A Piece of Work" during the 2010 Sundance Film Festival in Park City, Utah, Jan. 25, 2010. Reuters/Lucas Jackson

Actress Joan Rivers recently attacked Kristen Stewart in her new book “Diary of a Mad Diva” calling the “Twilight” star a "one trick pony," according to media reports.

The 81-year-old comedian and writer claimed that Stewart is “a person who slept her way to fame,” hinting at Stewart’s affair with Rupert Sanders, the director of her film “Snow White and the Huntsman.”

"Many stars only do one thing well. Of course, the best one-trick pony is Kristen Stewart, who got a whole career by being able to juggle directors' b****," Rivers reportedly wrote in her book.

According to Hollywood Life, the “In Bed with Joan” host, who is known for slamming celebrities, also targeted Pharrell Williams and Paris Hilton.

"No one is allowed to dress up anymore during Award Season. The networks have new decency guidelines, which insist that no more breasts, buttocks or genitalia show. Luckily, because of celebrities like Pharrell and his stupid hat, we'll still be able to see a*******,” Rivers reportedly wrote about the “Happy” singer.

About Hilton, she reportedly wrote: "It's all over the news that Angelina Jolie had a double mastectomy to prevent getting cancer. I think Paris Hilton should... step up to the plate and try to prevent STDs. It would be so easy for her. All she would have to do is have her knees fused together."

Rivers also reportedly mocked the frequent use of vampire as a theme for movies and TV shows: “They're everywhere: movies, TV, museums. Enough already!”

“If I want the life sucked out of me, I'll spend a long weekend with Bethenny Frankel,” she reportedly said, attacking the former “Real Housewives of New York” star.