When his mother falls ill, Dexter creates a robot to do her chores. Dee Dee gets hold of its remote control and wreaks havoc, forcing Dexter to create a second robot to counter Dee Dee's.

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 "Deedeemensional", Dee Dee time-travels to save Dexter from a monster. In "Magmanamus", Monkey goes up against a lava being that dislikes human-caused noise. In "Maternal Combat", when his mother falls, Dexter creates a robot mom to substitute for her.

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

Mandark Astronomanov, a new student at Dexter's school, seems to be superior to Dexter academically. Mandark forces Dexter to shut down his lab so that Mandark's lab can gain more power. However, with the help of Dee Dee, Dexter manages to destroy Mandark's lab.

Rerun of "Dexter's Laboratory", the first "What a Cartoon!" pilot.

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.

Dee Dee and her friends, Lee Lee and Mee Mee, enter Dexter's lab and wreak havoc. Dexter clones himself to stop them, but the girls too make clones of themselves.

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

Monkey encounters Simion, an intelligent anthropomorphic chimpanzee who seeks vengeance on humans for turning him into his current state.

Monkey's birthday party is interrupted by Barbequor an intergalactic villain who plans to eat the planets, and his sidekick, the Silver Spooner.

To clone a dinosaur with an incomplete DNA sequence, Dexter uses his dog's genetic code to fill in the gaps.

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

After Dee Dee steals his critical invention, Dexter ventures into her room to find it.

Monkey encounters an alien hunter named Huntor and must fight him to save Agent Honeydew and Commander Chief.

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.

With only one television in their apartment, Major Glory, Krunk, and Valhallen disagree on what to watch: Major Glory's televised capture of the Disgruntled Postman, TV Puppet Pals, or the monster truck pull.

Dexter and Dee Dee's father buys a video game for them to play, but the game sucks Dexter inside when he plugs in the cartridge, and it is up to Dee Dee to bring him out.

Dexter has a crush on his teenage babysitter Lisa. 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.

Valhallen loses his magic ax and starts turning into a nerd, forcing Major Glory and Krunk to enter his room to find it.

When Dexter's nightmares become frequent and problematic, he invents a machine that allows him to have nice dreams, as long as Dee Dee can operate it properly while she is awake.

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.

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

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".

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