With more than 270 episodes, The Big Bang Theory is the longest-running sitcom of all time. Since the release of the pilot back in 2007, the show gains tons of popularity.By 2012, TBBT was number two in terms of ratings, and it ultimately reached the number one ranking in its eleventh season. The success of the show even inspired a spin-off series about the childhood of the fan-favorite character, Sheldon Cooper.

But just like any other TV series, there are some parts of the show that even hard-die TBBT fans and the cast members are not very fond of. A great example is the Serial Ape-ist storyline. Both the creator of TBBT and Kaley Cuoco, who played Penny all throughout the show’s 12 seasons, absolutely hated this storyline.

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How Kaley Cuoco Landed The Role Of Penny In The Big Bang Theory After Another Actor Was Fired

Although nowadays Kaley Cuoco is most well-known for her portrayal of Penny in The Big Bang Theory, her professional acting career goes way back. Cuoco made her first feature film appearance in the thriller Virtuosity (1995). Following that, she landed several supporting roles in film and television. And in 2002, Cuoco had her breakthrough role when she played Bridget Hennessy on the ABC sitcom 8 Simple Rules (2002–2005).

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From 2007 to 2019, Cuoco starred as Penny on CBS’ The Big Bang Theory. Although, nowadays, it’s hard to imagine anyone but Cuoco playing Penny, this actress wasn’t the original choice for the role.

In Jessica Radloff’s book, The Big Bang Theory: The Definitive, Inside Story of the Epic Hit Series, it was revealed that Jodi Lyn O'Keefe had been originally cast to play Penny.

The actress, better known for playing Cassidy Bridges in the television series Nash Bridges, even filmed some scenes with Jim Parsons and Johnny Galecki before she was abruptly fired from the show. After that, other actresses, including Marisa Tomei, Elizabeth Berkley, Tara Reid, and Amanda Walsh, auditioned for the role. But, ultimately, it was given to Kaley Cuoco.

It’s clear that hiring Cuoco was the right choice. After all, her portrayal of Penny was not only beloved by fans of the show, but by the critics too. Cuoco got multiple awards for this role, including a Satellite Award, a Critics' Choice Award, and two People's Choice Awards.

The Serial Ape-ist Was A Recurrent Joke In The Big Bang Theory

In the episode, the Serial Ape-ist and its sequel, Serial Ape-ist 2: Monkey See, Monkey Kill, are two low-budget horror movies in which Penny starred.

Fans first learned about these movies in TBBT season 7, episode 1, when Penny reveals to Sheldon that she once did a topless scene in a low-budget film about a killer gorilla that was never released. Fast-forward to the seventeenth episode of that same season, Penny debates on whether to reprise her role in the Serial Ape-ist sequel.

By the end of the seventh season, Penny is cast in Serial Ape-ist 2, alongside Wil Wheaton. And the “ape-ist” movies are only mentioned again on three different occasions on the show: two times in season eight, and one time in season 10, when Penny attends the Van Nuys Comic-Con and signs autographs for fans of the film.

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Kaley Cuoco Wasn’t The Only One Who Hated The Serial Ape-ist Storyline

Despite enjoying her overall time in the show, Kaley Cuoco has admitted there were some TBBT storylines she didn’t like or completely hated. That’s the case of the “serial ape-ist” storyline.

In Chapter 16 of The Big Bang Theory: The Definitive, Inside Story of the Epic Hit Series, Kaley Cuoco admitted that she truly hated filming this storyline. “The worst experience was filming Serial Apeist and getting covered in f–king hair from head to toe,” she says. “I was like, ‘Really, you guys? This is what’s happening?’ And Chuck just thought it was so funny. He loved it. I never understood why,” she wrote.

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And it turns out that Cuoco wasn’t the only one that hated this storyline. The TBBT creator, Chuck Lorre hated it too. “Doing a show within a show — writing the ‘bad’ scenes that she’s in, in an otherwise good show — was not our finest moment. The goal was legitimate, which was to put her in a bad move and see her struggling to make something work,” he admitted.