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.
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.
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 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.
On his birthday, Dexter makes himself invisible so that he can find out whether his parents have bought him the Major Glory action figure he always wanted.
After Dexter’s pencil rolls to the back of the school bus, Dexter goes to retrieve it, but legend says that no one has ever returned from the back of the bus.
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.
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.
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.
