Dee Dee enters the land of her imaginary friend Koosalagoopagoop.

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

Following a mishap in his lab, Dexter ends up in the old, long-abandoned part of the lab, and discovers his early, neglected inventions.

Dexter tries to move the Moon, which is blocking Saturn and its “science waves” (which is what makes it a “good day for science”).

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.

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

In a parody of Tom and Jerry, Dexter accidentally switches his brain with that of a mouse’s and must avoid his mother when she decides to exterminate him.

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

Two robots (Martin Mull and Fred Willard) escape from Dexter’s lab in order to have a better life and avoid Dexter’s totalitarian rule.

Dee Dee’s father trains her to fight a gang of bicycle-riding rogues dressed as ninjas who target her paper route every morning.

Mandark enters a surfing contest and tries to cheat his way to victory to win Dee Dee’s heart from another surfer.

Dexter and Dee Dee enter tryouts to become Major Glory’s sidekick. When Dee Dee wins, Dexter realizes that fancy costumes are not the only criterion to become a superhero.

Dexter shrinks his parents and puts them into a model of their house for observation.

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.

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 parents remember their first date and dance together.

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

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

Dexter is given detention after accidentally shouting out the answer to a test question.

When Dexter is bitten by a clown’s dentures, he begins turning into a mad clown every night, terrorizing the town with his mayhem, and only Dee Dee, who knows mime, can stop him.

Dee Dee goes and plays in her own “lab” after being kicked out of Dexter’s.

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.

To keep himself from forgetting anything important, Dexter uses a device to copy his memories, which causes a mayhem in his own head.

To prevent himself from being taken away by aliens for experimentation, Dexter tricks Dee Dee into going instead, but he regrets his decision after realizing how much he cares for her.