A moon base is destroyed by a spaceship with a cluster of gumballs on its head. Later, at Sea World, dolphins are dying mysteriously. Zigra kidnaps two men and two children (one of whom is a Coke addict - Coca-Cola that is) and starts causing earthquakes. The two six year olds somehow outwit Zigra and help their incapacitated fathers escape. The Zigra Woman, who can use her eyes to put people into comas, then chases them all over Sea World like an extended Benny Hill skit. Somewhere in this movie Gamera finally shows up, fights Zigra, who turns into a giant swordfish.
Gamera's back, and just in time to save Japan from Gyaos, a mysterious bat-like creature awakened by a volcanic eruption. As in the first Gamera movie, a young boy establishes an emotional link with Gamera, and the two work together, with the help of the world's scientists, to put and end to Gyaos' violent rampage.
A giant creature attacks Japan during the World Fair and it's up to Gamera to stop it. But the monster injects Gamera with its offspring and a research team must take a craft into Gamera's body to eliminate the parasite.
After a treacherous expedition to retrieve a giant opal, disaster strikes as the opal reveals itself to be an egg which spawns Barugon, demon dog from Hell! Armed with a deadly tongue and cold beams, Barugon wreaks havoc on Japan. Gamera comes to save the day.
Aliens kidnap two children and take them to another planet for the purpose of getting knowledge from their brains, but Gamera follows and tries to rescue them.
A group of aliens from another planet head for Earth with the intentions of conquering it. Their first ship is destroyed in transit by the giant flying turtle Gamera. A second ship makes it to Earth and captures two Boy Scouts and holds them captive so that Gamera will not attack them. The aliens then implant a remote control device into the monster's neck and use the great turtle to attack Tokyo.
A nuclear explosion in the far north unleashes Gamera, the legendary flying turtle, from his sleep under the ice. In his search for energy, Gamera wreaks havoc over the entire world, and it's up to the scientists, assisted by a young boy with a strange sympathic link to the monster, to put a stop to Gamera's rampage.
An atomic explosion awakens Gammera, a giant fire breathing turtle monster from his millions of years of hibernation.