A pet project started by a filmmaker to satisfy their massive ego. One can usually tell because they'll take two or more of the roles of producing, directing, writing, and/or acting. If they're playing the protagonist, expect a "Jesus by a different name" vibe (compare Mary Sue). Most vanity films revolve around a blunt political message. While total nobodies are capable of and expected to create vanity films, the term is generally reserved for established celebrities throwing caution to the winds.