While out for dinner at a pizza restaurant, Dexter tries to slow down the “Whack the Weasel” machine to win a stuffed Monkey doll before Dee Dee does. Security captures him for tampering with the machine, and he falls into the hands of a mad scientist.

After staying up late at his lab, Dexter oversleeps, waking up one minute before his school bus arrives. With no time to do his morning chores and homework, he pulls out a secret prototype device, which converts his last 30 seconds into 30 minutes.

To fix their apartment’s plumbing, Krunk and Valhallen go to the basement, where they meet Ratman (Maurice LaMarche), a diminutive vigilante raised by rats (a parody of Batman).

Dexter makes his own Major Glory action figures so that he can join the neighborhood’s Major Glory gang, but gets into serious trouble when the rest of the gang finds out that none of his action figures are original.

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 and Mandark’s fathers become embroiled in a conflict after trying to defuse one between their sons.

When Dexter is asked to bring his mother to school, he disguises Dee Dee as her so that she can take her place, but Dee Dee does not behave like their mother.

Dee Dee teaches Dexter how to live life her way instead of being lonely and purely focused on science.

While fighting Comrade Red and his gang, Krunk falls in love with his equivalent in their gang, She-Thing (Kath Soucie).

Dexter’s newest invention looks like a hat, so Dee Dee takes it and wears it around town.

Dexter is forced to play dodgeball by his P. E. teacher (Michael Pataki). Constantly failing, Dexter builds a robotic exoskeleton to defend himself.

When Dexter discovers that Beau, Dee Dee’s new boyfriend, has similar interests as him, Dexter tries to steal Beau’s attention from Dee Dee.

With everyone out of the house, Dexter’s father decides to spend the time dancing.

Mandark plans another scheme to get rid of Dexter. Everything in this cartoon is to the tune of Mandark’s trademark laugh.

On his birthday, Dexter makes himself invisible so that he can find out whether his parents have bought him the Major Glory action figure he always wanted.

When Dee Dee eats a contaminated apple, she turns into a monster every time when she tells Dexter what to do.

Dexter finds out that all of Mandark’s plans are taken from a comic book.

Dexter is forced to take Dee Dee to the zoo. There, she ends up trying to save an ostrich with disastrous results. Dee Dee and the ostrich switches their places.

When Dexter becomes the victim of Dee Dee’s snowballs, their father teaches him to be the snowball terror that he used to be in his youth.

Rerun of “Dexter’s Laboratory”, the first What a Cartoon! pilot.

Dexter refuses to admit that blondes have more fun, so Dee Dee secretly dyes his hair blond to prove it to him.

Dexter and his father enter a golf tournament, but Dexter’s father proves inept at the sport.

During a trip to his grandfather’s house, Dexter learns that the outwardly boring old man has a lab just like his own.

Dexter brings the cavemen who first discovered fire back from the past, who acts like Dee Dee and starts smashing the lab.