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 reluctantly takes piano lessons from Professor Williams (Paul Williams), but when the Professor stumbles onto Dexter’s lab, he discovers that Dexter has more musical talent than he thought.

Dee Dee goes and plays in her own “lab” after being kicked out of Dexter’s.

After being denied dessert by his parents for not eating his vegetables, Dexter uses radiation therapy so that he can like vegetables, but it causes a severe side effect that turns him into an Incredible Hulk-like character if he goes too long without them.

A little girl with big eyes falls in love with Dexter and follows him everywhere after he returns a toy she dropped earlier, much to his chagrin.

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.

Dee Dee inflates Dexter’s hydro-plasmatic suit and constantly floats in the air, prompting Dexter to bring her down.

Dexter is given detention after accidentally shouting out the answer to a test question.

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

Dexter accidentally gives himself telepathy that he cannot shut off when trying to overhear his father’s thoughts to figure out what he got for his birthday, causing everyone to accidentally read his own mind.

Since his studying is interrupting his favorite TV shows, Dexter creates a helmet to absorb the shows directly. However, the plan backfires when he randomly snaps into television-based outrages.

Dexter’s father tries to get himself and Dexter to his fishing spot before sunrise so that they can start fishing before others arrive.

Major Glory forces Krunk and Valhallen to tidy up their apartment for his Uncle Sam, who is coming over for a visit.

Old Dexter And Old Dee Dee’s talks about the glory days, and his sister is still there to inject her opinions, telling him what really happened.

Dexter creates a robot to assist him, but the robot starts controlling his lab and tries to destroy Dexter.

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.

Mandark gets in touch with nature.

Rerun of the second What a Cartoon! pilot.

Dexter and his friends are targeted by a bully at school for their multicultural accents.

Monkey must defend the city from a giant underground lava monster, Magmanamus (Brad Garrett), who cannot sleep because of the noise created by its residents.

Dexter is disappointed when he ends up at an Amish farm instead of a high-tech farm for summer camp. His attempts to modernize the Amish family do not go well.

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.

Banned from watching a late-night movie due to his young age, Dexter uses his technology to artificially grow into adulthood, but Dee Dee tampers with his machine, causing Dexter to turn into an old man.

In need of an assistant to operate his latest invention, Dexter performs a brain transplant on Dee Dee to make her smart enough to fulfill the role. With her new brain, Dee Dee proves to be more intelligent than Dexter.