Pink Flamingos (1972)

In the outskirts of Phoenix, Maryland, a notorious underground figure known as Divine lives with her eccentric family, quietly reveling in their infamy. Their peace shatters when the devious Connie and Raymond Marble, who run a horrifying black market baby ring, aim to dethrone Divine as the "filthiest person alive." The Marbles' schemes grow increasingly vile, involving a spy, a box of human feces, and a grotesque birthday party ambush.