Dexter and Mandark are both outperformed by a new girl at school, so they reluctantly team up to get rid of her.

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.

When Dexter cannot reach anything in his lab, he makes himself more flexible by combining himself with bubble gum.

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

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.

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.

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

Monkey narrates a documentary of the future of laboratories and sciences.

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.

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

Dexter invents a belt whose wearer can do anything backwards, but mayhem occurs when Dee Dee gets hold of the belt’s directional switch.

When Dee Dee befriends a turtle that gets severely injured, Dexter not only heals it, but gives it superpowers.

When Dee Dee takes photographs of his lab, Dexter goes on an adventure to retrieve the photos before his parents see them.

When Dexter cannot get the ice cream truck to stop for him, he creates a series of obstacles to do so.

Due to overworking his brain, Dexter’s mind shuts down, making him act idiotic.

Dexter creates a device that turns people into hideous blobs. His parents then sell the device in a garage sale, where it ends up in Mandark’s hands.

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’s mom fights another woman at the supermarket for some new latex gloves.

Dexter’s father plays golf with his kids.

On Mother’s Day, Dexter’s mother has her gloves taken by the family so that she can relax and not do housework, but she is unable to adjust to a life where she cannot keep the house clean.

Dee Dee befriends a sasquatch during a camping trip, but Dexter is determined to capture the sasquatch.

Quackor returns to battle Monkey in Dexter’s Lab until Quackor lays an egg; then the two fall in love.

Dee Dee wins a golden diskette, earning her a free trip to the laboratory of Professor Hawk (Tom Kenny), one of Dexter’s favorite scientists.

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.

Created and narrated by a six-and-a-half-year-old boy named Tyler Samuel Lee, who sent a tape containing the episode’s audio to Cartoon Network,[9] the story follows Dexter and Mandark’s robot “brother” Computress teaming up to make Mandark’s head shrink.

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

Dexter creates a new type of ink that lets him command people to do whatever he wants. However, when Mandark gets his hands on it, Dexter is the one that becomes commanded.

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

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

After Dexter orders and eats a giant burrito, he suffers severe stomach pains. Believing a test the computer gave him, he assumes that he has only 30 minutes to live.