Dexter refuses to admit that blondes have more fun, so Dee Dee secretly dyes his hair blond to prove it to him.

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.

Dee Dee gets a song stuck in her head, which is actually a virus. Dexter and Mom soon catch it, and Dexter has to reverse the effects of this. He succeeds at the end, not knowing that Dad also caught it.

Dexter’s father tries to watch a golf tournament, but is constantly interrupted by his wife, Dexter, and Dee Dee.

When their father makes Dexter and Dee Dee switch rooms, Dexter believes that Dee Dee is destroying his lab and destroys her room in retaliation.

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.

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.

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

Dexter tries to figure out how Dee Dee keeps entering his lab every time he kicks her out through one entrance and seals it.

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

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.

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.

During a trip to his grandfather’s house, Dexter learns that the outwardly boring old man has a lab just like his own.

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

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

After fellow Justice Friend White Tiger helps Valhallen stop a super-villain, the latter invites him to spend the night in his apartment, forgetting that Major Glory is allergic to cats.

Dexter falls victim to one of his own inventions and sends Dee Dee back in time to warn his past self about the consequences, but the past Dexter proves hard to convince.

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

Dee Dee’s new dance moves annoy Dexter to no end.

Mandark plans another scheme to get rid of Dexter. Everything in this cartoon is to the tune of Mandark’s trademark laugh.

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.

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.

Dexter tries to avoid being pushed into the family’s new swimming pool by his father, since he cannot swim and is afraid of water.

Dexter travels to the moon and finds that aliens are planning an invasion on Earth, and he uses his Robo-Dexo 2000 to stop them. It turns out that they only were interested in purchasing sweaters for the winter.

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

On his birthday, Dexter makes himself invisible so that he can find out whether his parents have bought him the Major Glory action figure he always wanted.

Dexter’s parents and Dee Dee have their minds taken over by an alien life form that escaped from Dexter’s lab.

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

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

Dexter participates in the “Annual Soapbox Derby down Volcano Mountain”. This episode is a spoof of the popular Japanese manga/anime Speed Racer. In this episode, the movements and dialog deliveries of the characters are similar to anime. While Dexter parodies Speed Racer and his father parodies Pops Racer, Monkey parodies Chim-Chim and Dee Dee parodies […]

Dexter finds the exact opposite of his family, a hyperactive boy who is like Dee Dee and has scientist parents who are like Dexter. Sensing to fit in, he switches places with the boy.