Courtney Shayne is the main antagonist of the 1999 film, Jawbreaker.
She is portrayed by Rose McGowan who also played Paige Matthews in the seasons 4 - 8 of the t.v. show Charmed.
She was the most popular girl at Reagan High School. She ruled the school with her friends Julie, Marcie, and Liz Purr. They were known as "The Flawless Four". Though at the time, Liz and her shared rule of the high school. In Courtney's case, she ruled the school with terror and domination. Liz on the other hand ruled with a tender hand and was described as the Princess Diana of Regan High. This did not sit well with Courtney.
One day, on Liz's 17th birthday, they surprised her with a prank. They were masked and gagged her with a Jawbreaker and stuffed her in the trunk of a car. They were going to take her to a surprise birthday breakfast and pull various other pranks on her. Unknown to them is that while they were laughing away at what they had just done, the Jawbreaker had logged into Liz's throat, causing her to choke to death. When they opened up the trunk to take her picture of her being surprised, to their horror, she was dead.
Courtney later devised a plan to where they would bring her back to her home and make it looked like she was raped. However, Fern Mayo, the school's outcast teen girl was charged by their teacher to bring her her homework and she over heard their argument about what to do about Liz. They heard her and gave chase. Courtney offered her a make-over and teach her how to be popular. After a bit of hesitation as well as Julie advising her against it, Fern accepted.
After the make-over, they renamed her Vylette. To the student body, she was a new student. She also took the place of Julie whom Courtney cast out of their group for defying her. Sometime during all of this, Courtney went to a local bar and picked up a man, took him to Liz's place and made it that they had sex. The man was presumably arrested for the crime.
However, much like the Frankenstein monster turned on his creation, Vylette would become more popular than Courtney. This did not sit well with Courtney at all. She confronted Vylette. Though Vylette was not responsive to her threats. Later on, Courtney had her revenge. She made posters which would reveal Vylette's true identity. She made hundreds of copies and posted them all over the school. After the humiliation, Vylette took back her name, Fern and teamed up with Julie and Julie's new Boyfriend, Zack to get even with Courtney. They could not think of anything.
Meantime, Courtney was like other girls in the school were getting ready for the prom. While this was happening, Julie found recorded audio evidence of Courtney being responsible for Liz's death. At the prom, things seemed to have been going well, that is until with Zack able to rig the audio equipment to playback the recording of Courtney saying, "I killed Liz, I KILLED THE TEEN DREAM. Deal with it." over and over. The students turned against Courtney, shouting obscenities and throwing the flowers from their prom suits at her as she attempted to run for the door, and at the end of the crowd Julie took a picture of Courtney's humiliation and despair. Her final fate is unknown, but it's assumed that she was arrested for the death of Elizabeth Purr.