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

A little girl with big eyes falls in love with Dexter and follows him everywhere after he returns a toy she dropped earlier, much to his chagrin.

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.

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.

Dexter and Koos must save Peepers to keep the land of Kooz from disappearing. However, they must contend with a villain who is determined to make the land of Kooz disappear forever.

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

Dexter is forced to take Dee Dee to the zoo. There, she ends up trying to save an ostrich with disastrous results. Dee Dee and the ostrich switches their places.

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.

Unable to ride in a roller coaster due to his height, Dexter creates a device to make himself taller.

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

Dee Dee builds a tree house and allows everyone inside except Dexter, in revenge for the times he kicked her out of his lab.

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.

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

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

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

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.

With everyone out of the house, Dexter’s father decides to spend the time dancing.

When an intelligence test grades Dexter as “average”, he shuts down his lab and tries to live life like a normal kid.

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

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

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

After staying up late at his lab, Dexter oversleeps, waking up one minute before his school bus arrives. With no time to do his morning chores and homework, he pulls out a secret prototype device, which converts his last 30 seconds into 30 minutes.

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.