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.

When Dexter’s friends become tired of his complicated traps and cheating while playing a role-playing game, they put Dee Dee in his place. She changes the style of play, which annoys Dexter but impresses his friends.

Dexter studies the potato, and when he is fascinated by its power to light up a light bulb, he tries to use it as an energy source.

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.

After watching a horror film, Dexter and his father become easily frightened.

To fix their apartment’s plumbing, Krunk and Valhallen go to the basement, where they meet Ratman (Maurice LaMarche), a diminutive vigilante raised by rats (a parody of Batman).

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

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

Dexter tries to emulate the barbarian hero of his favorite comic book.

When Dee Dee eats a contaminated apple, she turns into a monster every time when she tells Dexter what to do.

Dexter accidentally becomes Dee Dee’s foot when the two fuse together. Now, they have to wait 24 hours to reverse the fusion.

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.

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.

A nature documentary team observes “Blackfoot” (Dexter) and “Slim” (Dee Dee) in their “natural habitat”.

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

Dee Dee dares Dexter into building her a giant robot similar to his Robo-Dexo 2000. They then team up to try to save an island’s population from being destroyed by an erupting volcano using their giant robots.

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

Dexter’s father sleepwalks into Dexter’s lab. Dexter discovers this, and now has to escort him out of the lab without waking him up, which proves more difficult than thought.

When Dee Dee claims that anything can be hers because Dexter “doesn’t have his name on it”, he invents a label-making gun.

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

When Dexter is asked to bring his mother to school, he disguises Dee Dee as her so that she can take her place, but Dee Dee does not behave like their mother.

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.

Following the destruction of his lab by Dexter and Dee Dee (in the episode Dexter’s Rival), Mandark turns to magic to beat Dexter at the science fair.

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

Dexter and Dee Dee’s secret decoder rings hold the keys to joining the Action Hanks and Pony Puff fan clubs respectively, but they interchange the clues by mistake, causing them to switch clubs.

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

When Dexter and his friends go looking for a “Star Check” convention, they accidentally end up at a “Darbie” doll convention.

When an electrician comes to Dexter’s house to repair a blown-out fuse, he accidentally stumbles onto his laboratory, and Dexter enlists him to repair the lab.

Dexter finds out that all of Mandark’s plans are taken from a comic book.

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

Again tired of being short, but mindful of his past failures, Dexter decides to make everyone shorter than himself.