While diving in the sea near the West Indies, Dr. Darian and Brock are startled when they are attacked by a bizarre mutant life form...a creature composed entirely of seaweed, which continues to grow increasingly larger as the plant beast merges with more and more seaweed. The two divers barely escape the plant creature's two huge tendrils as they frantically swim back to the Calico. There they call upon Godzilla to deal with the creature, and while the Seaweed Monster is no match for Godzilla, the Kaiju King can't seem to severely injure the plant creature's physical substance. As the Seaweed Monster menaces a nearby inhabited island, Dr. Darian notices that a severed piece of the creature completely dried up after excessive exposure to sunlight. Thus, she directs Godzilla to drag the Seaweed Monster onto land, where the searing tropical sunlight eventually causes the plant creature to wither and die.
After their ship is damaged in a storm, the team ends up on an uncharted island. They soon discover the island is inhabited by a cyclops monster. Worst of all, Godzilla cannot reach them because of a force field guarding the island. The team must escape the island and somehow not let the creature escape and threaten the world.
While helping the crew out of a typhoon, Godzilla wanders through a mysterious pink fog. Before long, the strange fog causes Godzilla to start shrinking. Even worse, a fly also inhaled the gas and is now growing to gigantic proportions and seems to be targeting Godzuki and Brock. The others must find a way to get Godzilla and the fly back to their normal sizes.
The team makes a fascinating discovery: A German U-boat from World War I trapped in an iceberg. After Godzilla frees it, the team is shocked to see the crew of the U-boat still alive and they also believe the war is still going. They manage to convince them the war is over, but then a giant octopus attacks the U-boat, with Pete and Brock inside. Godzilla must stop the octopus before the sub is destroyed.
The team gets caught in a strange-looking hurricane and end up in a city in the clouds. The inhabitants explain they are there to escape an evil dragon in their old world. Unfortunately, the dragon follows them there. To make matters worse, after seeing Godzilla defeat the dragon, the inhabitants turn hostile and want Godzilla so they can have him destroy the dragon. The team must rescue Godzilla and keep him from falling into the wrong hands.
After a lightning strike, a cyborg whale, (a prototype sub used for scientific purposes) suffers a malfunction and steams out of control with Pete and Brock inside. Even worse, the whale is on a collision course with Honolulu, Hawaii. The others and Godzilla must rescue Pete and Brock and stop the whale before it destroys Honolulu.
While blasting, a mining team inadvertently causes a rock slide that opens the side of a mountain exposing a large valley. A short while later the Calico runs aground in a river and while exploring the nearby area wanders into the opening and discovers a valley full of giant plants and insects. While attempting to save the team Godzilla is initially paralyzed by a Black Widow Spider bite. During the battle to save the team the only means of escape is blocked so the team must find a way to escape and also prevent the insects from escaping the valley.
While observing the moon with a powerful new telescope located far out in the ocean. Quinn and Brock notice a strange volcanic eruption on the moon that launches an object hurtling towards the earth. A mysterious creature emerges and wreaks havoc on shipping and seems to affect gravity on the earth. The team and Godzilla must stop it before it causes worldwide devastation.
When a new island is formed in the Pacific Ocean, the team investigates. Aftershocks from the islands formation end up trapping them in the volcano on the island, which they find is inhabited by giant lizards that eat lava. Worst of all, Godzilla is unable to reach them because he is also trapped by the seismic activity. The others must find a way to escape without Godzilla's help.
When a new weather satellite is mysteriously shot down, the team traces the missile's source to an island near Australia. They find the island fortified and under the command of a terrorist organization known as COBRA. The terrorists imprison the team thinking they are spies. The nuclear reactor on the island begins to suffer problems that threaten to cause an explosion that could destroy the island. Godzilla must rescue the team, stop the COBRA group, and prevent the reactor from exploding.
A UFO lands in the Arctic and the team is sent to investigate. They discover a group of ice people from another planet that plan to destroy the Earth with an asteroid the size of the Moon. Majors and Quinn are taken prisoner and Godzilla, Brock, and Godzuki are frozen. Pete must free the others before the asteroid destroys the world.