Serial Ape-ist is a low-budget horror movie that Penny did when she first moved to LA Los Angeles. Its plot involves a genetically engineered and sex-crazed killer gorilla on a rampage. Penny appears in a scene topless in the shower where her character is attacked and killed by the gorilla.Penny tells Sheldon about the movie in "The Hofstadter Insufficiency" (S7E1). She thought that no one knew about the movie since it never came out; however, Howard found it online shortly after the guys met her in the "Pilot ". Even Sheldon had watched the movie. Leonard shows the movie (and his beautiful girlfriend) to his scientist colleagues on his North Sea expedition in the summer of 2013.
In "The Friendship Turbulence" (S7E17), Penny told the guys she has turned down a part in the sequel to Serial Ape-ist (Serial Ape-ist 2: Monkey See, Monkey Kill). Later when her car breaks down and she needs money, she calls back for the part, but finds out that it has been given to someone else. Later, she is again offered the part and takes it, but is reluctant since the movie is so bad. She seeks the advice of Wil Wheaton who later she finds is in the movie playing an orangutan and her boyfriend/mad scientist. When Penny tries to get the director to have another take on her latest scene he fires her because they don't need her after that.
Girl: (Played by Penny, sighing) I'm so glad the police finally caught that psychotic genetically engineered ape.
(Shadow of ape with ax behind her)
- After the credits, Chuck Lorre's vanity card #451 shows a picture of the sequel's script. The title reads "SERIAL APE-IST 2: Monkey See, Monkey Kill, written by Vince Gilligan". Under the title, a hand written note reads: "Thanks Vince, You're a good sport, bitch ! [signed] Chuck".
- There is a little-known straight-to-video movie from 2002 called ''Planet of the Erotic Apes'', alternatively titled "Babes in Kong-Land", starring soft-core actress Julie Strain. ("Queen of the B-Movies") Is this the reference?