Monkey’s birthday party is interrupted by Barbequor (Robert Ridgely), an intergalactic villain who plans to eat the planets, and his sidekick, the Silver Spooner (Rob Paulsen).
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.
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.
After Dexter orders and eats a giant burrito, he suffers severe stomach pains. Believing a test the computer gave him, he assumes that he has only 30 minutes to live.
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.
When Dee Dee tries to cut off a piece of her hair, she accidentally cuts off one of her pigtails. Dexter gives her a potion to make her missing hair grow back. However, Dee Dee squirts too much of it in her hair, and Dexter must return Dee Dee’s hair back to normal.
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.
When his family is suffering from the flu, Dexter tries his best to not acquire the illness, but his efforts are thwarted by a sick Dee Dee’s presence in his lab.
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.
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.
With only one television in their apartment, Major Glory, Krunk, and Valhallen disagree on what to watch: Major Glory’s televised capture of the Disgruntled Postman, TV Puppet Pals, or the monster truck pull.
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.
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.
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.
Dexter’s father sleepwalks into Dexter’s lab. Dexter discovers this, and now has to escort him out of the lab without waking him up, which proves more difficult than thought.
