Dee Dee’s imaginary friend Koosalagoopagoop (Dom DeLuise) suddenly comes to life and starts annoying Dexter.

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

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.

Dexter falls in love with a new girl at his school, but he cannot win her heart until Dee Dee helps him with poetry

After Dee Dee declares that she can beat Dexter in any game, Dexter challenges her to a series of games in his lab, though he prefers to win by cheating.

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

Dexter’s parents get him a bike for exercise, but he’s unable to catch Dee Dee on her inline skates.

Dexter creates a device to make a lifelike superhero comic, with his sister villain “Deestructa”.

When Dee Dee tries to cut off a piece of her hair, she accidentally cuts off one of her pigtails. Dexter gives her a potion to make her missing hair grow back. However, Dee Dee squirts too much of it in her hair, and Dexter must return Dee Dee’s hair back to normal.

After being denied dessert by his parents for not eating his vegetables, Dexter uses radiation therapy so that he can like vegetables, but it causes a severe side effect that turns him into an Incredible Hulk-like character if he goes too long without them.

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.

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 calls upon the “shoe gnomes” to repair his shoes, but he seeks out Dee Dee to rid himself of them afterwards.

Dee Dee’s stuffed animals come to life and roam the house when Dee Dee uses a formula that brings inanimate objects to life, which delights Dee Dee, much to his dismay.

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

When Dexter accidentally hits his mother with a ray of energy, she gains superpowers.

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

Dexter’s Magic Uncle Fergel O’Reilly (Mark Hamill) pays a visit to the family.

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

After working in his lab all night creating his latest invention, Dexter tries to sleep, but he is constantly interrupted by Dee Dee.

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

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

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.

After watching an Action Hank movie on television, Dexter grows a synthetic beard to try to be cool, but the police mistake him for Action Hank himself.

Dexter’s life story, from his birth to the creation of his secret laboratory, is retold as an opera.

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

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.

When Dexter neglects his metal-eating pet bug, it begins eating his lab as revenge.

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.

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.

Dexter’s father is challenged to an arm wrestling match by a man named Earl at a truck stop. Stunned at the strength of Earl and his determination to beat his father, Dexter attaches a robotic arm to his father to enable him to win.