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 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.
Dexter accidentally gives himself telepathy that he cannot shut off when trying to overhear his father’s thoughts to figure out what he got for his birthday, causing everyone to accidentally read his own mind.
Mandark gets inside Dexter’s computer system and creates a computer virus, so Dexter must follow him inside and kick him out from cyberspace. However, Dee Dee has other plans in mind.
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.
Dexter creates a new type of ink that lets him command people to do whatever he wants. However, when Mandark gets his hands on it, Dexter is the one that becomes commanded.
When Dexter’s friends become tired of his complicated traps and cheating while playing a role-playing game, they put Dee Dee in his place. She changes the style of play, which annoys Dexter but impresses his friends.
Dad decides to give the car a retouch, but keeps breaking things and saying he will fix it later. After having enough, he pushes the car over a cliff, and below it are other crushed cars, meaning this was not the first time.
Dexter makes his own Major Glory action figures so that he can join the neighborhood’s Major Glory gang, but gets into serious trouble when the rest of the gang finds out that none of his action figures are original.
Since his studying is interrupting his favorite TV shows, Dexter creates a helmet to absorb the shows directly. However, the plan backfires when he randomly snaps into television-based outrages.
After fellow Justice Friend White Tiger helps Valhallen stop a super-villain, the latter invites him to spend the night in his apartment, forgetting that Major Glory is allergic to cats.
Not interested in hearing Dee Dee’s long-winded story, Dexter gives her a silencing formula to keep her quiet, but it instead turns her into a giant monster still bent on telling her story. When he realizes that nothing can make her quiet, he becomes a giant monster himself.
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.
