Pink Flamingos (1972) on Netflix

The filthiest person alive, Divine, is using the codename Babs Johnson while living in a trailer in the woods with her mother Eddie, who loves eggs, her mad hippie son Crackers and her mate Cotton. The envious couple Connie and Raymond Marble, abduct and impregnate female hitchhikers to sell their babies to gay and lesbian couples. The money they make is invested in heroin that's sold in schools. They hire Cookie to have sex with Crackers and spy Divine to compete for the title of "the filthiest people alive". When the competition begins, Connie and Raymond Marble learn why Divine has this title.