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 and Mandark bring the Abraham Lincoln and George Washington faces respectively on Mount Rushmore to life and make them fight each other to determine who is the best.

Dexter’s lab is threatened with repossession unless he can repay his debt to NASA. When Dee Dee wins the same amount in a lottery, he decides to steal her money out of desperation.

Dexter is trapped in his school by the janitor in revenge for making him work late everyday due to Dexter’s habit of leaving the school last everyday.

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.

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

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.

Dexter and Dee Dee enter tryouts to become Major Glory’s sidekick. When Dee Dee wins, Dexter realizes that fancy costumes are not the only criterion to become a superhero.

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.

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

Dexter and his friend Douglas Mordecai must enter the girls’ bathroom to retrieve Dexter’s lunchbox, which was put in there by another student.

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

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.

After she expresses her desire to become a Pony Puff Princess, Dexter transforms Dee Dee into a horse with pink fur, and a yellow tail and mane.

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.

Parodying The Pink Panther, Dexter is trying to paint his lab blue, but Dee Dee wants to make it pink.

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.

Monkey’s birthday party is interrupted by Barbequor (Robert Ridgely), an intergalactic villain who plans to eat the planets, and his sidekick, the Silver Spooner (Rob Paulsen).

Dexter’s mother asks him to read a story to a sick Dee Dee. Dee Dee becomes bored of Dexter’s story and creates one of her own.

While on a date with Agent Honeydew, Monkey gets hypnotized by the music of the Organ Grindor (Jim Cummings), who commands him to rob Fort Knox.

When Dexter’s glasses break, he creates a new fad (wearing broken glasses) and becomes extremely popular at his school.

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 invents a robot parrot that happily repeats self-congratulatory comments he makes, but when it starts repeating things about his lab and escapes, he sets out to destroy it before it tattles to his parents.