The Son of Godzilla (ゴジラの息子, Gojira no musuko) is the third instalment of the Godzilla Sagaverse. In the film, Godzilla comes to the aid of his newborn son, who hatches from an egg on a remote island. Revealing a surprising paternal streak, Godzilla tries to teach his much smaller progeny how to use his powers. Meanwhile, the two must then battle various monsters, including praying mantises, a formidable spider, and others. Can Godzilla protect his curious tike from the gargantuans? It was followed by Godzilla vs. Gamera.
Eleven years after Godzilla's fight with the monsters Anguirus and Rodan, the duo have been looking for Godzilla since they lost to him. Now searching the world, they finally find Godzilla on Monster Island, an island inhabited by various monsters, including Godzilla himself, his son, and close friend Manda. With his son under attack from monsters, Anguirus and Rodan jump too Godzilla's aid to help him.
- Godzilla: The King of the Monsters and titular protagonist, Godzilla is a dinosaur mutated by the atomic radiation of the H-Bomb. While battling various monsters, Godzilla tries to train his son to be the monster prince.
- Minilla: The Son of Godzilla, Minilla aids his father in fighting various monsters, including the residents of Monster Island.
- Manda: The Goddess of the Sea, Manda is an ancient Japanese dragon-like sean serpent who is a close friend of Godzilla. She aids him and the others to defeat various monsters.
- Anguirus: The Killer of the Living, Anguirus is a giant ankylosaurus who somehow survived the extinction of the dinosaurs.
- Rodan: The King of the Skies, Rodan is a giant, irradiated pteranodon who like Anguirus somehow survived the extinction of the dinosaurs.
- Zilla Junior: A giant, mutated marine iguana-like monster and the only surviving offspring of the original Zilla.
- Gorosaurus: A giant Tyrannosaur-like monster, Gorosaurus is another friend to Godzilla.
- Varan: The Unbelievable Monster from the East, Varan is a giant, prehistoric monitor lizard-like tri-phibian monster that can fly with gliding abilities.
- Deutalios: A giant fish/rat-like monster and an acquaintance of Godzilla.
- Maguma: A prehistoric, walrus-like reptilian monster.
- Titanosaurus: The Aquatic Dinosaur, Titanosaurus is a prehistoric marine reptilian-like monster with a desire for revenge against anyone for disturbing his slumber.
- Hedorah: The Smog-Monster, Hedorah is a giant, alien tadpole-like creature who is a reoccurring enemy of Godzilla’s.
- Kumonga: The Queen of Monster Island and the world's top predator, Kumonga is a giant spider and the main antagonist of the Monster Island Community.
- Ebirah: The Horror of the Deep, Ebirah is a giant lobster and one of the many primary antagonists of Monster Island.
- Gyaos: The Shadows of Evil, the Gyaos are a species of malevolent, carnivorous vampire bat-like monsters.
- Kamacuras: A giant, mutated praying mantis.
- Ookondoru: Two giant condors living on Monster Island.
- Gezora: The Cephalopod Being, Gezora is an alien squid-like monster.
- Kamoebas: The Megalo Mata Mata, Kamoebas is a giant, mutant rock turtle-like monster.
- Ganimes: The Armored Crab Monster, Ganimes is a giant stone crab-like monster.
- Anguirus and Rodan arrive at Monster Island and see Godzilla and Manda
- Hedorah Appears
- Godzilla is victorious and makes new friends
- Mogeura Battles the Monsters of the Island