Dexter and Dee Dee’s father buys a video game for them to play, but the game sucks Dexter inside when he plugs in the cartridge, and it is up to Dee Dee to bring him out.

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

Dee Dee’s imaginary friend Koosalagoopagoop (Dom DeLuise) suddenly comes to life and starts annoying Dexter.

Dexter falls victim to one of his own inventions and sends Dee Dee back in time to warn his past self about the consequences, but the past Dexter proves hard to convince.

When Dee Dee takes photographs of his lab, Dexter goes on an adventure to retrieve the photos before his parents see them.

Dexter’s father tries to get himself and Dexter to his fishing spot before sunrise so that they can start fishing before others arrive.

Dexter and his friends are targeted by a bully at school for their multicultural accents.

Quackor returns to battle Monkey in Dexter’s Lab until Quackor lays an egg; then the two fall in love.

When Dee Dee befriends a turtle that gets severely injured, Dexter not only heals it, but gives it superpowers.

Dexter thinks that a crazy homeless person balancing electronic devices on his head and muttering gibberish is a genius trying to contact aliens, so he takes him home.

When Dexter learns that Dee Dee is trying to make a science project alone, he decides to help her, but she does not want his help.

When Dexter becomes the victim of Dee Dee’s snowballs, their father teaches him to be the snowball terror that he used to be in his youth.

Dexter travels to Mars to find intelligent life, unaware that Dee Dee has stowed away in his space capsule. After Dee Dee gets covered in red dirt, Dexter thinks she is a real-life Martian.

Monkey must defend the city from a giant underground lava monster, Magmanamus (Brad Garrett), who cannot sleep because of the noise created by its residents.

Dexter’s father is left to watch the kids while his wife visits her sister.

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 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

In this crossover with Dynomutt, Dog Wonder, Blue Falcon (Gary Owens) comes to Dexter’s house and asks him to rebuild an injured Dynomutt.

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.

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 lab is threatened with repossession unless he can repay his debt to NASA. When Dee Dee wins the same amount in a lottery, he decides to steal her money out of desperation.

When Dexter’s glasses break, he creates a new fad (wearing broken glasses) and becomes extremely popular at his school.

Dexter is disappointed when he ends up at an Amish farm instead of a high-tech farm for summer camp. His attempts to modernize the Amish family do not go well.