Penrod, who would rather hide in the haystall writing bloody adventure stories, is obligated to appear in a children’s pageant as the Child Sir Lancelot. To further his humiliation, his mother and sister dress him for the performance in a silk bodice, stockings, and his father’s flannel underwear. Ridiculed by fellow cast members Maurice and Marjorie, he appropriates and dons a pair of the janitor’s capacious overalls, which brings down the house and ruins the pageant.

Penrod uses his Sunday School money to buy candy and attend a lurid cinematic melodrama about the evils of drink. Caught daydreaming in school, he attempts to excuse his inattention by describing the film’s events as factual and pertaining to his visiting aunt and cousin. His mother hears about the story and demands that her husband suitably punish their son.

Before dancing class adjourns for the summer, a cotillion is planned for the children to demonstrate their manners and dancing skills. Penrod aspires to invite Marjorie to be his partner, but Maurice beats him to it. He is subsequently turned down by eleven other girls, leaving only an eight-year-old who sobs when he asks her. Penrod and his friend Sam plan revenge on Maurice by concocting a mixture of hair tonic, outdated smallpox medicine, and mouthwash and selling it to Maurice as “lickrish water.” The potion makes Duke ill, but, inexplicably, Maurice enjoys the drink with no ill effects. Penrod then gets out of attending the dance by pretending to fall off the barn roof.

Two young African American brothers named Herman and Verman catch a raccoon and proudly sport deformities, such as having an amputated finger and being tongue-tied. Penrod and Sam stage a sideshow featuring these boys, the raccoon, some rats, and a dachshund. Posters and publicity bring several neighborhood children to the show, for which Penrod acts as ringleader. When attendance at subsequent shows lags and a rich boy sneers, Penrod adds this boy to the attractions, noting that his surname is the same as that of a currently infamous murderess. Featuring him as the murderess’s nephew attracts many customers to the show, until the boy’s snobbish mother, incensed and threatening lawsuits, closes down the attraction. Penrod and Sam’s mothers insist that their fathers punish the boys, but each father secretly slips his son a quarter instead.

Penrod sings loudly while his sister Margaret and her guitar-playing boyfriend Bob are trying to “spark.” Bob gives Penrod a dollar to leave, and Penrod buys himself an old accordion and some candy with which to serenade and treat Marjorie, who is babysitting her younger brother. Penrod bribes the little boy and enjoys Marjorie’s company. Penrod’s father secretly throws away his accordion, whereupon Penrod attends a local carnival, buying and consuming enough junk food to make him very ill for three days. Margaret is as enraged as her parents are at Bob for having made possible Penrod’s eating spree. She breaks up with him. Marjorie likewise snubs Penrod because her own little brother has gotten sick from swallowing the money Penrod gave him.

An older boy from a tough neighborhood, Rupe Collins, starts to hang out with Penrod, who begins to imitate Rupe’s bullying speech and actions. Penrod becomes intolerable to his family and friends, encouraging Rupe to abuse Sam, until Herman and Verman leap to Sam’s defense by attacking Rupe with a rake, a lawn-mower, and a scythe. Rupe runs home, and Penrod resumes his normal behavior.

When the barber calls him a “little gentleman,” he puts Penrod in an ugly mood. The boy finds a kettle of tar, and when his friends,...