Dexter’s family goes to the beach, where Dexter tries to communicate with whales. He must rescue Dee Dee (dressed as a mermaid), when she is captured by manic pirates.
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.
Mandark disguises himself as Dexter’s mom to get into Dexter’s Lab. Unfortunately for Mandark, he now has to deal with Dexter, Dad, and Dee Dee’s requests, which are too much for him.
Dexter, Monkey, Agent Honeydew, the Justice Friends, Dee Dee, her imaginary friend Koosalagoopagoop, Mandark, his parents, and Dexter’s parents participate in a cross-country race a la Wacky Races.
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.
When his mother falls ill, Dexter creates a robot to do her chores. Dee Dee gets hold of its remote control and wreaks havoc, forcing Dexter to create a second robot to counter Dee Dee’s.
It is Career Day, and because Dexter is ashamed of his father, he creates a better father for himself. However, he soon discovers that his real father is much cooler.
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 and Mandark bring the Abraham Lincoln and George Washington faces respectively on Mount Rushmore to life and make them fight each other to determine who is the best.
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 catches the chicken pox, and Dee Dee tells him a ridiculous tale that if he keeps scratching them, he will turn into an evil chicken. Dexter completely restrains himself so that he will not have to scratch it; unfortunately, he is unable to resist and his nonstop scratching eventually does just that.
