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.

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

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.

Not interested in hearing Dee Dee’s long-winded story, Dexter gives her a silencing formula to keep her quiet, but it instead turns her into a giant monster still bent on telling her story. When he realizes that nothing can make her quiet, he becomes a giant monster himself.

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

Dexter is upset that Dee Dee is more photogenic than him, so he transforms his face into a handsome one for his next Picture Day.

When Dexter’s father tries to teach his son sports, he realizes that Dexter is not athletic.

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

Dexter’s life story, from his birth to the creation of his secret laboratory, is retold as an opera.

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.

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.

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 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.

Dee Dee is hired by Mandark’s parents to babysit him.

Dexter and Dee Dee realize that they make a good team, so they decide to do stuff together, but doing so makes things worse.

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

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

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.

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

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.

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.

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

After a Puppet Pals marathon, Krunk dreams the Puppet Pals are attacking puppet versions of Major Glory and Valhallen.

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

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

Dexter and Dee Dee go to South America to catch the legendary chupacabra.

Dexter makes an angst-ridden trip to the hardware store to buy a new light bulb for his lab.

When Dee Dee hides the core of Dexter’s nuclear lamp, he must decipher her clues within one hour to find it.

In a fit of rage, Dexter dumps Dee Dee’s favorite teddy bear into the garbage. An upset Dee Dee begins to behave oddly, prompting Dexter to go to the garbage dump and get it back.

Dexter’s school and parents decide to send him to college. He ignores his fellow students, who prefer to “party now, study later”, until his mind finally snaps from the workload.

The U.S. army invades Dexter’s lab under the mistaken impression that aliens are using it as a base of operations on Earth, and Dexter must convince them that this is actually his lab, and also has to keep this a secret from Dee Dee.