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 and Dee Dee compete against each other on a game show.

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

Mandark gets in touch with nature.

Dexter makes his own Major Glory action figures so that he can join the neighborhood’s Major Glory gang, but gets into serious trouble when the rest of the gang finds out that none of his action figures are original.

Dexter’s parents discover that he is making false excuses to get out of physical education and now Dexter must pass a physical exam if he wants to pass P.E. and move up a few grades.

When Dee Dee causes Dexter to mistakenly take a book from the library without checking it out, they sneak into the library at night to put it back.

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

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.

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

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 tries to prove to Dee Dee that Santa Claus is not real and is in fact their father in disguise. He ends up paying for his mistake when he has captured the real Santa Claus.

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

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

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.

Dexter’s mother attempts to support him during a chess tournament but does nothing but embarrass him.

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

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

When Dexter discovers that Beau, Dee Dee’s new boyfriend, has similar interests as him, Dexter tries to steal Beau’s attention from Dee Dee.

When Dexter tries to inject himself into an ill Dee Dee to find a cure to the common cold, he accidentally ends up inside his dog, believing that Dee Dee is infected with a dog virus.