When his family is suffering from the flu, Dexter tries his best to not acquire the illness, but his efforts are thwarted by a sick Dee Dee’s presence in his lab.

Dee Dee accidentally shuts down Dexter’s lab, and he has to power it back. In the process, Dee Dee attempts to keep Dexter from finding out what she really did.

After watching a horror film, Dexter and his father become easily frightened.

To learn more about girls, Dexter camouflages himself and enters Dee Dee’s room, where she is having a sleepover with her friends Lee Lee and Mee Mee. He gets caught by the girls, who force him to take part in their activities.

Mandark disguises himself as Dexter’s mom to get into Dexter’s Lab. Unfortunately for Mandark, he now has to deal with Dexter, Dad, and Dee Dee’s requests, which are too much for him.

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.

Dexter, Monkey, Agent Honeydew, the Justice Friends, Dee Dee, her imaginary friend Koosalagoopagoop, Mandark, his parents, and Dexter’s parents participate in a cross-country race a la Wacky Races.

After working in his lab all night creating his latest invention, Dexter tries to sleep, but he is constantly interrupted by Dee Dee.

Tired of bathing, Dexter laminates himself to stay clean.

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

Rerun of the second What a Cartoon! pilot.

To keep himself from forgetting anything important, Dexter uses a device to copy his memories, which causes a mayhem in his own head.

Monkey narrates a documentary of the future of laboratories and sciences.

Dexter and Mandark drill underground to expand their labs, but end up running into each other’s work. So they agree to share the lab, inducing chaos.

When Dexter cannot reach anything in his lab, he makes himself more flexible by combining himself with bubble gum.

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.

Dee Dee builds a tree house and allows everyone inside except Dexter, in revenge for the times he kicked her out of his lab.

Dee Dee’s imaginary friend Koosalagoopagoop (Dom DeLuise) suddenly comes to life and starts annoying Dexter.

Loading the player... During a trip to Japan as part of a student exchange program, Dexter accidentally releases a giant monster with an axe-like head from a volcano, forcing him to enlist the aid of his family to defeat it.

Dexter creates a magnetic field to keep Dee Dee away from him, but it malfunctions, causing them to stick together.

When Dee Dee claims that anything can be hers because Dexter “doesn’t have his name on it”, he invents a label-making gun.

Dee Dee learns a new game that can predict the future events.

When Dexter catches Dee Dee killing ants, he shrinks them both to take her inside an ant colony so that she can learn how organized the ants are.

Dexter finds a lost Labrador Retriever, but when he teaches the dog to speak human language, he turns out to be very annoying, prompting Dexter to find the dog’s owner.

Dexter and Dee Dee must travel to Chinatown to get their fingers unstuck from a Chinese finger puzzle.

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.

Unable to ride in a roller coaster due to his height, Dexter creates a device to make himself taller.

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

Dexter tries to make himself and Dee Dee older to see an R-rated movie, but he accidentally makes everybody else babies instead.

Dexter invents a belt whose wearer can do anything backwards, but mayhem occurs when Dee Dee gets hold of the belt’s directional switch.

Dexter and Dee Dee experiment with coffee after seeing how it energizes their parents in the morning.

Dexter and Dee Dee listen in on their parents’ conversation; they are playing Scrabble, but the way they talk makes it sound like Dad was cheating on Mom