"Godzilla and his youngster, the Gimantises, and now a Spiga! Huh, it's an island of monsters!"
— Goro Maki, in the Titan Productions dub of the Walter-Reade TV version.
Titled Kaijū-tō no Kessen Gojira no Musuko (Monster Island's Decisive Battle: Godzilla's Son) in Japan, Son of Godzilla is the eighth film in the Godzilla franchise, notable for the introduction of Minya and further Godzilla development into a hero.
The testing of a weather control system on Sollgel Island is hampered by a nosy reporter and the discovery of large mantises. A strange cry from the island makes things go further awry, exploding the weather balloon and spreading radiation that mutates the mantises into Kamacuras which dig up an egg. They are about to make the baby Godzilla into their meal when the King of the Monsters himself shows up, offing the two Kamacuras and adopting the baby called Minya as his son. The first day of parenting starts off awkwardly, with Minya being a bit too cowardly and Godzilla not having the patience to deal with children. When Minya defends a woman living on the island from the last Kamacuras, the Giant Spider Kumonga is awakened and Godzilla must discover his Papa Wolf nature before his son is dissected...
Followed by Destroy All Monsters in terms of production whereas Godzilla vs. Hedorah resumes Showa Godzilla's storyline.
This film contains examples of:
- Abusive Parents: Godzilla isn't particularly thrilled about being Minilla's adoptive father at first, best shown when he is less than impressed with the newborn infant and reluctantly allows him to climb on to his tail to carry him to safety, not to mention Goji treats Minilla rather harshly as he decides to train him to be a decent fighter (Granted, this is more justified considering Minilla is living on an island full of bigger, nastier kaiju that want to make a meal out of him). Goji starts to mellow when Minilla begins to prove his combat abilities and finally earns his respect by helping him beat Kumonga.
- Beam-O-War: Minilla actually engages in one with Kumonga briefly, using his heat-ray to deflect the arachnid's webbing.
- Godzilla does as well. Impressively despite shooting spider webs but big, Kumonga manages to stalemate Godzilla's Atomic Breath years before Mechagodzilla's eye lasers would.
- Bad Guys Do the Dirty Work: Kumonga disposes of the final Kamakuras.
- Big Creepy-Crawlies: The Kamacuras, two meters tall even before hit with a dose of radiation.
- Bottle Episode: Sans the prologue (which still takes place away from civilization), the entire film is shot on an island, All the monsters are operated with wires, and only two monsters require suitimation: Godzilla and Minilla.
- Cabin Fever: While the researchers are all a little flustered from being cooped up on Solgell for several months, Furukawa (played by Yoshio Tsuchiya) has it the worst. By the time the radioactive storm wrecks the island, he's so fed up with the place he begins threatening the others at gunpoint before literally trying to swim off the island. Godzilla showing up the moment he tries to doesn't make matters any better...
- Conservation of Ninjutsu: Three Kamakuras fighting Godzilla ends with two dying extremely quickly to one atomic blast apiece. The third one makes it all the way to the climax of the film and withstands multiple shots of Godzilla's breath.
- Determinator: Dr. Kusumi continues his research for the benefit of the world in spite of increasingly unfavorable odds. Two Godzillas stomping around are just a few of those. Goro is also pretty determined to get a story out of the personnel when he drops in, being the intrepid journalist and all.
- Distinguished Gentleman's Pipe: Dr. Kusumi is often seen ambling around with one.
- Dub Name Change: In the English dubbing script (also used as a basis for the Titan dub), Kamacuras and Kumonga were anglicized as Gimantis and Spiga, respectively. Saeko's name was also changed, to Reiko in the Frontier dub, and Riko in the Titan dub.
- Eviler than Thou: Kumonga kills the last Kamakuras, immediately showing it is a bigger threat.
- Eye Scream: Godzilla gets a drop of Kumonga/Spiga's venom shot into his right eye after letting his guard down for a moment, resulting in a lot of agony and the first ever Godzilla Face Palm.
- Giant Spider: Kumonga. At 45 meters tall, he's easily one of the biggest in fiction.
- Gone Horribly Wrong: The first radioactive sonde climate experiment goes awry after the mysterious radio waves from the center of the island jam the frequencies sending commands to the apparatus, and Kusumi and the others aren't able to detonate it in time, resulting in the opposite of the intended freezing effect: A fucking hot radioactive thunderstorm. Keep in mind that this is all Minilla's fault.
- Hong Kong Dub: The listenable but unpolished Frontier dub easily qualifies, though it was in fact dubbed in Tokyo.
- Impairment Shot: There's an out of focus glimpse of Kumonga seen through Godzilla's eye in the final brawl.
- Intrepid Reporter: Goro Maki, who parachutes onto the island and refuses to leave until he finds out what's going on with the scientists.
- Kill It with Fire: Godzilla catches on pretty quick that the Kamakuras are extremely flammable.
- Godzilla and Minilla finally set their dreadful arachnid adversary aflame by firing their heat-rays together simultaneously. Either this Kumonga got better or another of its kind showed up, with the massive blizzard raging around its flaming "carcass" and whatnot.
- Leitmotif: This being a Masaru Sato scored picture, the soundtrack is a bit more of a Theme-and-Variations Soundtrack-type score than the usual Ostinato stuff, with several memorable motifs, like Minilla's theme, Riko's theme, Godzilla and the Gimantises' jazzy dirges, and the whimsical experiment preparation march.
- Monster Popsicle: Godzilla and Minilla are forced to go into hibernation by the final and successful test, which covers the entire island, both monsters included, in snow.
- Minimalist Cast: There are even fewer players in the U.S. TV version, which cuts the prologue.
- Mythology Gag: Minilla accidentally swipes a boulder at a Kamakuras with his tail, but it deflects it with its foreleg, hitting Minilla in the face. The Kamakuras then claps in amusement.
- Not-So-Harmless Villain: Kumonga seems at first glance like your generic Giant Spider monster... except he spits a highly resistent type of silk which can restrain larger, stronger kaiju like Godzilla and Minilla. He uses this to his advantage in his fight with Godzilla and would have likely devoured the Big G had it not been for Minilla's intervention.
- Papa Wolf: Godzilla. He immediately decides to defend hatchling Minilla from the Kamakuras, and later intervenes to save him from Kumonga.
- Snow Means Death: If used as a weapon, the Weather-Control Machine is described as being a more dangerous weapon than the atomic bomb because of this. When they decide to do it in order to bury the island in snow and ice in the ending, however, Godzilla and Minilla undergo Harmless Freezing until the island becomes tropical again.
- Vile Villain, Saccharine Show: While most of the film is Lighter and Softer, with Minya providing cute antics and Godzilla's violence limited to an isolated island, Kumonga is a genuinely frightening creature, not to mention he comes dangerously close to making a meal out of Godzilla and Minilla at the end.
- Weather-Control Machine: A rare instance of this being used for benevolent purposes.
- The Worf Effect: Narratively, the Kamakuras mainly exist so stronger monsters can kill them. Godzilla kills two effortlessly, then later Kumonga gets the last one, demonstrating to the audience how dangerous he is.
- You Have to Burn the Web: The only real effective way of escaping Spiga/Kumonga's threads.
