Dr. Shock uses his Master Mix Monster Machine to turn his assistant Igor into an electricity-absorbing monster.

The Spinner steals a $1,000,000 tiara.

The Paper Doll Man steals a top secret plan and is out to steal the second part.

Professor Conroy and Buzz unveil the blueprints for the Spy Detector XK-00-7 at a Maximum Security Building. Unfortunately, the blueprints are targeted by the Spyder Man.

Beamatron steals a priceless painting from a ship.

The Burrower uses his burrowing machine to steal half a million dollars from the bank and dig ten miles down to his lair.

Upon an encounter with Buzz at the wax museum, Mr. Menace uses his monsters Godzonka, Gorillis and Cyclaws in an attack upon San Francisco.

Timeatron uses his time cabinet to bring villains from the past to pillage for him.

Smogula freezes the Impossibles and seals them within a cave, so they will not interfere with his plans to conquer Empire City.

A giant alien brain arrives on Earth and captures Buzz and Frankenstein Jr.

The Speck uses a formula to shrink himself in order to photograph top secret plans.

To get the Impossibles out of the way, Fero uses his fiddle to transport them to different planets.

A giant alien brain arrives on Earth and captures Buzz and Frankenstein Jr.

Mother Gruesome invents a machine that brings villainous storybook characters out of their stories to help her with her crimes.

Televisatron transports the Impossibles to different television shows.

The alien Zargon unleashes his warrior Destructo to conquer Earth.

The Dauber uses a special brush where anything he paints becomes real.

Aquator has stolen a secret formula from a scientist who is friends with Big D and shrinks himself to microscopic size in order to get all the microscopic creatures to become large.

Plant Man thaws the last three prehistoric plants (the Carnivorous Chewer, the Creeping Crusher and the Fire-Breathing Snapdragon) from a glacier and then sprays them with his Obedience Ray in a plot to eliminate Buzz and Frankenstein Jr.

Professor Stretch causes havoc with his elastic abilities.

The Dragster has stolen a valuable item.

The Mad Inventor has invented the Double Identity Duplicator Projector to create living images he can control.

The Spinner returns and steals a priceless pooch.

The Surfer takes pictures of a top secret submarine.

The Junk Man creates the Colossal Junk Monster in a plot to eliminate Frankenstein Jr.

Spraysol steals top secret documents.

Buzz and Frankenstein Jr. guard the Navy's new Hydrotomic Submarine to prevent Dr. Hook and his aquatic monsters from stealing it.

The Sculptor turns people into statues.

The Archer steals a priceless violin and a million dollars.

Zorbo the Great creates a genie and plans to use its three wishes in order to defeat Frankenstein Jr. and conquer the world.

The Inflator creates giant balloon monsters to help him commit crimes.

The Diamond Dazzler steals a precious diamond in order to awaken the genie within.

Birdman and his robotic birds Vulturo, Rodantus, and King Condor abduct two astronauts and hold them for a ransom of $1,000,000.

The Paper Doll Man returns and causes trouble.

A witch named Cronella Critch robs a charity for orphans party.

Sertano the Satellite King, an alien from Galaxy X, uses a gravity ray in order to get Earth to surrender. Buzz and Frankenstein Jr. must defeat Sertano's robots in order to defeat him.

The Twister is stealing precious jewels.

Professor Stretch returns and creates a rubber monster to help him.

The Tapper transmits himself over phone lines.

The Angler steals secret space research.

To perform a crime wave in London, Baron Von Ghoul creates robotic versions of the horror movie monsters the Electroflying Firefly, the Menacing Mummy, and the Wicked Werewolf.

The Ringmaster puts on a circus and robs from those who attend.

Billy the Kidder is a cowboy who rides a robotic horse and plans to rob the U.S. Mint.

The Mad Inventor has invented the Monstermobile and uses its many gadgets to commit crimes.

Dr. Futuro comes from the 40th century to the twentieth century to steal a million dollar gold brick.

The Clutcher uses an invention that brings his gloves to life.

Mr. Menace uses his putty monster to steal a $1,000,000 coin collection and even kidnaps Buzz. It is up to Frankenstein Jr. to rescue Buzz and defeat Mr. Menace.

Mr. Instant uses his insta-gun that can make anything in an instant.

The Batter kidnaps a baseball star and holds him for ransom.

Dr. Spectro creates three giant ghoulish ghosts in order to take over Penciltrainia.

Mr. Ice and his henchman Freezer Freezer freeze the city in order to take it over.