Scary Movie

On Halloween night, Drew Decker receives a threatening phone call while home alone. Chased outside by a masked killer, she is stripped to her bra and panties before being stabbed in the breast, removing one of her silicone implants. Her father, who is distracted by receiving fellatio from his wife, accidentally hits her with his vehicle, and she looks at her murderer just before being fatally stabbed.

Cindy Campbell meets with her boyfriend Bobby Prinze and her friends, Brenda Meeks, Ray Wilkins, Greg Phillippe, Buffy Gilmore, and Brenda's stoner brother Shorty. News teams, including reporter Gail Hailstorm, converge on the school due to Drew's murder. Gail seduces Buffy's intellectually disabled brother, Special Officer Doofy, to elicit information. While in class, Cindy sees the killer watching her from outside before receiving an ominous note. She then realizes Drew was murdered exactly one year after she and her friends accidentally killed a man by hitting him with a car and dumping his body in a lake. After football practice, Greg finds a photo of his small penis on his locker saying "I KNOW" on it. Believing Ray took the photo, he confronts him and their friends.

Cindy tells them about the note, insisting they contact the police, but Greg beats her instead, fearing imprisonment. At Buffy's beauty pageant that evening, the killer murders Greg in plain view, while the audience mistakes Buffy's pleas for help as part of her dramatic reading. Buffy eventually wins the pageant and forgets Greg. The killer attacks Cindy while she is home alone, but retreats when she contacts the police. Bobby arrives and is arrested after a cellphone, knife, and gloves fall out of his pocket. As Cindy spends the night at Buffy and Doofy's, she receives a call from the killer.

The following day, Bobby is released from jail. Buffy is beheaded by the killer with a cleaver while in the girls' locker room. That night, Gail and her cameraman Kenny go to a makeout spot to film a murder on camera. After they catch the killer murdering teenager Heather, he chases them into the woods and murders Kenny. Gail later gives a snot-filled apology to Kenny's family. Later that night, Ray and Brenda go to the movies to see Shakespeare in Love, where Ray is stabbed through his ear in a bathroom stall through a glory hole. The killer nearly murders Brenda, but angry movie patrons, fed up with her rude and obnoxious behavior in the theater, stab her to death to make her stop and for spoiling Shakespeare in Love and several other films like Thelma and Louise, The Fugitive, Schindler's List, the Jackie Chan movies, Boogie Nights, and Big Momma's House. Meanwhile, Cindy is having a house party, hoping for safety in numbers. One of her friends Tina is killed while getting beer from the garage. During the party, Cindy and Bobby go upstairs and have sex. The killer gets stoned with Shorty and his friends in the basement, but accidentally kills all but Shorty.

After Cindy and Bobby have sex, the killer stabs Bobby and disappears. She gets a gun from a drawer and Bobby follows. Shorty comes up from the basement warning about the killer, but Bobby shoots him. Ray arrives on the scene, still alive, with a voice changer. Bobby and Ray confront Cindy in the kitchen, announcing they will only kill her and her father, and that they are merely copying the real killer. Bobby admits to being gay and Ray's lover, while Ray denies it. The plan backfires when Ray stabs and kills Bobby out of anger and outrage because his favorite show, The Wayans Bros., has been canceled after five seasons without getting a final episode. The real killer abruptly arrives, murdering Ray and fighting Cindy until she kicks him out a window. However, the killer vanishes before the police arrive, to Cindy's dismay.

At the police station, Cindy and the sheriff discover that the killer was not David Keegan, the man accidentally killed by the teens last year. He was really Doofy, who was faking his disability and has escaped with Gail Hailstorm after removing his disguise. The sheriff and Cindy find his discarded backpack with his mask and knife in the street, and Cindy begins screaming but is hit by a car.