In Baltimore, Maryland, Divine, who has been named “The Filthiest Person Alive” by a tabloid, takes on the alias, “Babs Johnson,” and goes into hiding in a mobile home outside town. There, she is accompanied by her son Crackers, her friend Cotton, and her mother Edie, who suffers from mental illness and an obsession with eggs. On another side of town, Connie and Raymond Marble are scheming to overtake Divine as the filthiest person alive. Channing, the Marbles’ assistant, ushers a lesbian couple in to see Connie, who is arranging for the couple to adopt Noodles, a baby born in the Marbles’ basement to a young girl who died in childbirth while enslaved there. When Connie grants them the baby, the lesbian couple showers her with thanks, telling her what a good person she is. At a deli in town, Divine orders a large cut of meat, then hides it between her legs, and later, walking around, Divine urinates outdoors. Meanwhile, Raymond Marble exposes his genitals in the park before returning home to Connie. They meet with Cookie, who plans to spy on Divine by going on a date with Crackers. Connie explains to Cookie that she and Raymond want to prove they surpass Divine in filth, describing their primary business, a “baby ring” in which they keep two girls impregnated by Channing in their basement and sell their babies to lesbian couples. Connie further explains that they invest the money in businesses around town, including pornography shops, and they also lend capital to heroin dealers who service inner-city elementary schools. Later, on her date with Crackers, Cookie meets Edie and Cotton at the trailer. Cotton pulls Crackers aside and begs him to make his sexual encounter with Cookie special because she plans to watch and wishes to see him do something new. When Crackers takes Cookie back to his shed, Cotton observes through the window as he forces Cookie to have sex with him while shoving two live chickens between their bodies. Meanwhile, the Egg Man comes by the trailer and kisses Edie hello while she screams excitedly about his delivery of eggs. That night, Connie and Raymond kidnap a hitchhiker, drug her, and take her to their basement to replace Noodles’s mother who just died. Channing masturbates into his hand then uses the semen to inseminate the new girl, still unconscious. Cookie calls the Marbles, tells them where Divine lives, and informs them of Divine's alias, Babs Johnson. Connie and Raymond rejoice that their plan to attack Divine is now in motion, grabbing a gift box they plan to send to her. The next day, Divine receives a delivery and reprimands the postal worker for coming onto her property. Angered that someone would send her a package, she opens the box from the Marbles, finding human excrement inside along with a note wishing her a happy birthday from “the filthiest people alive.” At their home, the Marbles catch Channing imitating them and lock him inside his room. Before Divine’s birthday party, the Egg Man proposes marriages to Edie and she accepts. The Marbles sneak up on the party, taking place outside Divine’s trailer, and watch as Divine opens various gifts such as a pig’s head and a hatchet. The Marbles call the police to report Divine’s party as “lewd and disorderly.” As the police approach, the partygoers grab weapons, kill the officers, and eat their flesh. After talking to a local gossip, Divine finds out that the Marbles are responsible for the excrement she received and locates their address. While the Marbles are out, Divine and Crackers break in and examine their home, licking everything in sight. Excited by their filthy act, Divine performs oral sex on her son, but is interrupted by a noise. Realizing someone else is in the house, Divine and Crackers find Channing, who leads them to the pregnant girls in the basement. The girls explain how they were kidnapped and impregnated, and Divine orders Crackers to free them. Once unchained, the girls castrate Channing. Meanwhile, the Marbles have set fire to Divine’s trailer, and when she finds it burning, she guesses they are the culprits. Soon after, the Marbles decide something is awry at their home when the furniture begins to move on its own, and they find Channing on the floor of the basement, castrated. Divine, Cookie, and Crackers ambush the Marbles and kidnap them. Later, three tabloid reporters arrive outside Divine’s destroyed trailer to witness the public trial and execution of the Marbles by Divine, Cotton, and Crackers. Divine announces to the reporters that she believes murder and cannibalism should be legal, amongst other things, and pronounces that filth is her life. After conducting a short trial, Cookie and Crackers tar and feather the Marbles, and Divine shoots them dead. The reporters take pictures and leave, and Divine’s crew happily plans their next move to Boise, Idaho. As Divine, Crackers and Cookie solicit a ride to Boise, Divine spots a dog having a bowel movement and rushes to eat the dog’s excrement.