Inspector Blooper, Jimmy and Gigantor head for the South Pole to stop Dr. Katzmeow, an evil genius who plans to take over the world starting with Antarctica.
Dr. Cats-meow captures Gigantor who escapes, but not before doctor Cats-meow manages to get a set of X-rays so he can build his own giant robot. Gigantor and Dr. Cats-meow's robot battle it out in Antarctica.
The Evil Captain Spider kidnaps Dr. Emeritus and brainwashes Inspector Blooper in an attempt to defeat Gigantor and gain control over a powerful new energy ray.
The team feels the sting of Captain Spider when he offers to exchange Dr. Emeritus for the powerful energy ray "Super Elex," which would allow him to take over the world.
Captain Spider now has the Super Elex but there is still one thing preventing him from taking over the world: Dr. Emeritus, the only one capable of building another one to use against him.
Forced to land in Australia, the team encounters General Von Q Ball, an old enemy of the Inspector's, who has a new weapon in his arsenal - a swarm of robotic bees.
Jimmy, Inspector Blooper and Gigantor go to a world conference on robots in India, and, disguised as holy men, encounter Dr. Diamond and his gang of deadly diamond smugglers.
Captain Danger has built two gigantic dinosaur robots in his undersea base and launches an attack on Dr. Brilliant's laboratory while Gigantor is being repaired. Could this be the end?
When robot saucers hijack trucks off the streets, Jimmy and the Inspector trace them to the factory of the notorious Nefarious, who has an arsenal of deadly robotic weapons.
Nefarious makes his attempt to take over the world using his mole drilling robot to steal a fortune from a bank. Now he can mount an all out attack that even Gigantor can't stop!
Dr. Bob Brilliant is kidnapped by the diabolical Oogleblabb, whose plan is to control Brilliant's mind and force him to build an evil version of Gigantor for his own evil purposes.
At the great Robot Parade, Gigantor is a big attraction. But without Jimmy at the controls, Oogleblabb manages to take control himself. Now he plans to use Gigantor to conquer the world.
Professor Dim Dome's daughter Dottie has been kidnapped by Oogleblabb, who will only release her in exchange for the professor's top secret MMM Multiplier weapon.
While exploring an ancient Inca temple, Professor Dig-A-Dug finds gold. But when he's captured by the mysterious Pisarro and his giant gorilla robot, Tiny, Gigantor is his only hope.
The oil fields of Morabia are threatened by rebel Prince Abdul Von Hothead, who uses a giant robot cobra built by Professor Flugle to take down Gigantor.
Jimmy and the team go on Safari in Africa to collect animals for a zoo, but a battle breaks out when Ping Pangians attack the Bongo Bongoans in a war over water.
With the water war still raging, Jimmy and the Inspector discover an underground dam on Bongo Bongo secretly built by neighboring Ping Pang as a power source. And a giant robot spider defends it!
With almost all their water stolen by the Ping Pangians, Bongo Bongo is vulnerable to an attack, especially when the Ping Pangians have a horrific new weapon - an atomic flame thrower - to use against Gigantor!
With his new energy machine attached to a car, Wizard Dee Doo can make it go 1000 miles per hour. But to do that, he needs Spedium ore which he has been mining from Goody Island... causing it to sink!
The only way to stop Evil Wizard Dee Doo's plan to take over the world is to find his secret base, but it's protected by a huge magnetic shield that even Gigantor can't penetrate.
When Double Trouble destroys a flight to Jupiter and threatens to destroy the next launch unless he gets the secret blueprints to the rocket, Gigantor is sent along for protection.
Dr. Brilliant is abducted by a flying saucer and taken to King Soress' secret base. There he's forced to work with another kidnap victim, Professor Pluto, to make new atomic weapons.
There's a mystery on Mystery Island: where'd everybody go? Someone has created a huge seaweed monster and Jimmy and Gigantor have to find the man before he makes more.
