When Dexter’s nightmares become frequent and problematic, he invents a machine that allows him to have nice dreams, as long as Dee Dee can operate it properly while she is awake.

Dexter’s family must rescue him from aliens.

Dexter is forced to play dodgeball by his P. E. teacher (Michael Pataki). Constantly failing, Dexter builds a robotic exoskeleton to defend himself.

Dexter’s school and parents decide to send him to college. He ignores his fellow students, who prefer to “party now, study later”, until his mind finally snaps from the workload.

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 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.

When Dexter cannot get the ice cream truck to stop for him, he creates a series of obstacles to do so.

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.

Dee Dee accidentally shuts down Dexter’s lab, and he has to power it back. In the process, Dee Dee attempts to keep Dexter from finding out what she really did.

Dexter and Mandark drill underground to expand their labs, but end up running into each other’s work. So they agree to share the lab, inducing chaos.

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.

Dee Dee and her friends, Lee Lee and Mee Mee, enter Dexter’s lab and wreak havoc. Dexter clones himself to stop them, but the girls too make clones of themselves.

Dexter finds a lost Labrador Retriever, but when he teaches the dog to speak human language, he turns out to be very annoying, prompting Dexter to find the dog’s owner.

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

Dexter and Dee Dee protect their mother’s muffins from their muffin-loving father while she is out shopping.

Dexter tries to avoid being pushed into the family’s new swimming pool by his father, since he cannot swim and is afraid of water.

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.

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

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.

When their father makes Dexter and Dee Dee switch rooms, Dexter believes that Dee Dee is destroying his lab and destroys her room in retaliation.

During a trip to Japan as part of a student exchange program, Dexter accidentally releases a giant monster with an axe-like head from a volcano, forcing him to enlist the aid of his family to defeat it.

Dee Dee inflates Dexter’s hydro-plasmatic suit and constantly floats in the air, prompting Dexter to bring her down.

Dexter and Dee Dee listen in on their parents’ conversation; they are playing Scrabble, but the way they talk makes it sound like Dad was cheating on Mom

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