Dexter and Dee Dee’s secret decoder rings hold the keys to joining the Action Hanks and Pony Puff fan clubs respectively, but they interchange the clues by mistake, causing them to switch clubs.
Suspicious that Dee Dee has not entered his lab even once on a particular day, Dexter shrinks himself and enters her room to spy on her. He soon becomes an unwilling character in Dee Dee’s doll story, but he believes the story to be real.
Dexter finds the exact opposite of his family, a hyperactive boy who is like Dee Dee and has scientist parents who are like Dexter. Sensing to fit in, he switches places with the boy.
It is Career Day, and because Dexter is ashamed of his father, he creates a better father for himself. However, he soon discovers that his real father is much cooler.
Dexter creates a satellite to clean stains off of his clothes, but it goes horribly wrong when Mir space station hits the satellite that Dexter created and the satellite becomes damaged, causing the fabric beneath each stain to be eliminated as well.
Mandark brings his lab duck Ducky for show and tell to counter Dexter and his lab monkey. Though neither creature displays remarkable characteristics at school, Ducky, unbeknownst to Mandark, is the alter ego of supervillain Quackor the Fowl.
After fellow Justice Friend White Tiger helps Valhallen stop a super-villain, the latter invites him to spend the night in his apartment, forgetting that Major Glory is allergic to cats.
Dexter and Koos must save Peepers to keep the land of Kooz from disappearing. However, they must contend with a villain who is determined to make the land of Kooz disappear forever.
After watching an Action Hank movie on television, Dexter grows a synthetic beard to try to be cool, but the police mistake him for Action Hank himself.
Dexter’s new device allows him to study for the next day’s French test while sleeping. It malfunctions, causing a single phrase (omelette du fromage) to repeat throughout the night, causing Dexter to wake up the next morning speaking nothing else except omelette du fromage.
Dexter has a crush on his teenage babysitter Lisa (Kath Soucie). When he finds out that she has a boyfriend, he sabotages their relationship and accelerates his age by ten years in an attempt to win her heart.
Dexter tries to prove to Dee Dee that Santa Claus is not real and is in fact their father in disguise. He ends up paying for his mistake when he has captured the real Santa Claus.
After Dexter’s pencil rolls to the back of the school bus, Dexter goes to retrieve it, but legend says that no one has ever returned from the back of the bus.
Dexter’s family goes to the beach, where Dexter tries to communicate with whales. He must rescue Dee Dee (dressed as a mermaid), when she is captured by manic pirates.
On Mother’s Day, Dexter’s mother has her gloves taken by the family so that she can relax and not do housework, but she is unable to adjust to a life where she cannot keep the house clean.
