"Big Fat Liar" is a 2002 family comedy film directed by Sean Levy. The story follows a teenager named Jason Shepherd, played by Frankie Muniz, who is known for his tall tales. When he tells a lie about a school assignment, it leads to unexpected consequences when a Hollywood producer, Marty Wolf, portrayed by Paul Giamatti, steals his story for a movie. To prove his point, Jason and his friend Kaylie embark on a mission to expose Marty. The film explores themes of honesty and creativity, showcasing the humorous challenges they face in their quest to reclaim Jason's story.