Both of the prophecies above are put to the test in Godzilla's 20th anniversary outing, Godzilla vs. Mechagodzilla (Gojira Tai Mekagojira, not to be confused with the Heisei and Millenium films). The monster that will try to save the people of Okinawa is King Caesar, the ancient guardian of the Azumi Royal Family. The monster that will destroy the world... is at first believed to be Godzilla, but after Godzilla's ally Anguirus is brutally attacked and wounded by the beast, people start to notice that something is off. When Godzilla attacks a refinery, another Godzilla appears. A vicious battle soon follows, where the first Godzilla soon sheds its skin in a fiery display to reveal a mechanical weapon of destruction: Mechagodzilla. The resulting battle ends in a draw, but questions remain. Who built Mechagodzilla, and why?
The answer to the above questions is that a race of aliens from "The Third Planet of the Black Hole," or Simians, have come to Earth to setup a new home for themselves. Instead of asking nicely, however, they've decided that the best option is to use Mechagodzilla to destroy a sizable portion of Japan to make way for their own settlement.
However, there is still the issue of the Azumi prophecy, and with it, King Caesar. If King Caesar can be awakened, then other monsters may soon follow, and so the Simians attempt to gain control of a precious statue that is instrumental to the legend to prevent the divine monster's awakening. Deciding to launch a two-pronged plan, the Simians capture an Earth scientist who is familiar with the technology they used to create Mechagodzilla, to speed up repairs, and send their own agents out to capture that damn statue. What follows are gunfights, INTERPOL agents with some bad hair-dos, and archaeologists fighting in a race against time to awaken King Caesar and stop the Simians. Fortunately, Godzilla is still alive, but will he be able to rejoin the fray before it's too late?
Well, yeah, of course he will.
Godzilla vs. Mechagodzilla was released in 1974, as the 14th Godzilla movie and in honor of the King of the Monsters' twentieth birthday. The film was directed by Jun Fukuda, with music by Masaru Sato and SFX work by Teruyoshi Nakano.
Followed by its direct sequel, Terror of Mechagodzilla.
Godzilla vs. Mechagodzilla features examples of:
- Alien Invasion: One where the aliens look like green-skinned gorillas. The Simians have built Mechagodzilla to eliminate the only obstacles to them taking over Earth: its assorted cast of Kaiju, starting at the top with Godzilla, who being the strongest of all the Earth's kaiju is their only formidable obstacle to world domination.
- Asian Lion Dogs: King Caesar is based on the Shisa, the Okinawan versions of these; his original name in Japanese is in fact "King Shisa". He's a stony, lion-like guardian entity who is awakened from his slumber by a Miko to protect the world from Mechagodzilla.
- Attack Reflector: King Caesar can reflect Mechagodzilla's eye beams with his own eyes.
- Beam-O-War: Mechagodzilla's Eye Beams vs. Godzilla's Breath Weapon. Interestingly, the result incapacitates both combatants, necessitating repairs for Mechagodzilla and downtime to regenerate for Godzilla.
- Being Watched: There are two instances of this.
- In Act I, a man is seen watching another man who is watching the professor. The same man who was being watched (and was watching the professor) reappears later in the movie on a boat because he's an alien trying to prevent King Caeser from being summoned.
- While Godzilla is fighting "Godzilla", the aliens are surveying the clash.
- Big Bad: Kuronuma, the leader of the Simian aliens who built Mechagodzilla and holds Professor Miyajima's daughter hostage to force him to rebuild Mechagodzilla into a more durable version.
- Big Damn Heroes:
- Just as Mechagodzilla is about to finish off King Caesar, the true King of the Monsters appears, giving Mechagodzilla something else to worry about. Downplayed in that even with Godzilla and King Caesar double-teaming it, Mechagodzilla holds its own for some time.
- "Blind Idiot" Translation: King Caesar's name in Japan is actually King Shisa, because he is a gigantic version of a traditional Okinawan shisa statue. Somehow this got corrupted as the nonsense term "Seesar" when the film was first translated, and later on Toho officially re-translated it as King Caesar. Not only is the new name essentially meaningless, it also doesn't sound remotely Japanese.
- Blood from the Mouth: Poor Anguirus.
- Blood Is Squicker in Water: Godzilla gushes with blood underneath Tokyo Bay after the beam explosion knocks him down into it.
- Call-Back: Anguirus emerges in the prologue sequence... somewhere... after being swallowed up by a fissure at the beginning of the previous film.
- Captain Obvious: "Space titanium? You mean it's from outer space?"
- Chekhov's Gun:
- Godzilla uses the lightning he absorbed earlier as a magnetic weapon against Mechagodzilla.
- The human protagonists' pipe.
- Chest Blaster: Mechagodzilla is packing one, and first uses it to take out the mountain that King Caesar is hiding behind.
- Crazy-Prepared: The Professor, who made a special pipe whose "bowl's metal includes astanopkaron" and "If you separate it in this way, magnetic waves will develop that will destroy the positive and negative electrodes", just because.
- Curb-Stomp Battle: Mechagodzilla's fight with Anguirus, and most of his fight with King Caesar, who only survived because of Godzilla's timely arrival. Even after he shows up, Mechagodzilla still inflicts its fair share of damage on the two.
- Darker and Edgier: While the next entry would prove to be even more grim, and in spite of its sillier elements such as King Caesar, the story is still darker than its direct predecessor for several reasons.
- Despite being grossly outmatched by Mechagodzilla, it takes his jaw being shattered for Angurius to finally give up.
- King Caesar counts as well. After Mechagodzilla catches on to his trick, he's obviously outclassed. But he was summoned to protect Okinawa, and he's gonna do so even if it kills him.
- Evil Knockoff: Mechagodzilla himself.
- Eye Beams: Mechagodzilla. Fortunately, King Caesar can reflect them.
- Foreshadowing: Mechagodzilla might be well disguised as Godzilla when he first appears, but does not copy Godzilla's iconic roar, and his atomic breath is yellow instead of blue, providing the first clues that something is off.
- Forgot About His Powers: During the scene where King Caesar and Godzilla try to flank Mechagodzilla from both sides, it turns its head 180 degrees to face King Caesar (who is coming from behind) so it can attack them both at once. But the only weapon mounted on the head is the eye beam that King Caesar has repeatedly shown to be able to absorb and fire back, with all the weapons he's vulnerable to mounted on the front of Mechagodzilla- so it's a bit unfortunate that King Caesar forgets he can do this when Mechagodzilla opens fire.
- Golem: King Caesar is a shisa-like kaiju-sized golem. He spends most of his time sleeping in an inanimate state inside a mountain and can be awakened with a song, which the family uses just in time to wake him up so he can help Godzilla fight his mechanical double.
- Gorn: This is definitely one of the, if not the goriest Godzilla film, at least of the Showa era.
- Hollywood Darkness: The scene where Keisuke chases one of the aliens on the deck of the cruise ship is so obviously set during the daytime with a filter slapped over that one wonders why they even bothered.
- Jawbreaker: Once Anguirus chips off a piece of Mechagodzilla's Fake Godzilla disguise, the machine immediately goes berserk and grabs Anguirus by the jaw, pulling them open until the monster's jaw is broken, bleeding all over the machine's hands. Mechagodzilla then slams Anguirus face-first into the ground for good measure. Given that in the Showa era timeline, this is the penultimate on-screen appearance of Anguirus prior to his appearance in Destroy All Monsters (set in the late-20th century), it's likely he needed quite a while to recover from his injuries.
- Killer Space Monkey: Simians, though they're not as brutish as most examples of the trope are.
- King in the Mountain: Quite literally with King Caesar, who is asleep inside a mountain waiting to be awoken, and returns to the mountain at the end, going back into his cave to sleep once more until he is needed again.
- Kubrick Stare: Godzilla gives surprisingly intimidating one as he comes ashore for Round 2 with Mechagodzilla, showing that this time, It's Personal.
- Lightning Bruiser: King Caesar is shown to be frighteningly fast when he closes the distance with Mechagodzilla, and hits hard enough to dent his near indestructible armor.
- Macross Missile Massacre: Mechagodzilla has dozens and dozens of missiles, lasers, and rockets at his disposal and he uses all of it in his battle against Godzilla and King Caesar.
- Meaningful Name: King Caesar, or Kingu Shisa. Refers to the shisa of mythology. Unfortunately, this is sometimes overlooked.
- More Dakka: Mechagodzilla, armed with Breath Weapon, laser eyes, a lightning beam fired from its chest, and missiles on its fingers and toes.
- New Powers as the Plot Demands: Godzilla himself. After his first defeat, he attracts lightning bolts to gain the power of magnetism and, oddly enough, heal.
- Mechagodzilla: A force field, which protects him from Godzilla's breath. He only uses this once, though. Justified, since it's reasonable to assume that this drains too much power to be used multiple times.
- Nigh-Invulnerability: Mechagodzilla is made from space-titanium and sports an unbreakable force field. Ultimately subverted, however, as it turns out Caesar's physical blows are strong enough to deal serious damage to it once Godzilla gives him the opening to do so.
- No-Nonsense Nemesis: From its first appearance, Mechagodzilla establishes itself as a villain who is not to be trifled with. It quickly sends Anguirus into retreat in brutal fashion, straight up blasts Godzilla with missiles upon revealing its true form, viciously beats down King Caesar once it adapts to Caesar reflecting its eye-beams, and when Godzilla arrives it relentlessly unloads its full arsenal on the heroic kaiju. While Godzilla vs. Megalon featured goofy theatrics from Gigan and Megalon, Mechagodzilla has no tolerance for such silliness; no posing, no taunting. Mechagodzilla carries out the orders of its creators with a cold and ruthless efficiency like a 50-meter tall Terminator, shooting first and not asking questions period. As the penultimate foe in the Showa series (with Titanosaurus joining it in the following sequel), Mechagodzilla gave Godzilla one last legitimate threat before his hiatus.
- Off with His Head!: How Mechagodzilla is finally defeated due to Godzilla's new magnetic based powers, as Godzilla's able to pull the machine towards him where he can then twist its head off its shoulders.
- Precision F-Strike: A mild one, but in a mid-70s' Godzilla movie it really stands out. The Simian leader spouts this gem before unveiling Mechagodzilla in his true form: "Damn Godzilla! You're mistaken if you think your powers are a match for Mechagodzilla!"
- Quizzical Tilt: Godzilla gives one when Mechagodzilla sheds his disguise.
- Sadly Mythtaken: Subverted with King Caesar. The Shisa is considered a guardian beast in Okinawan folklore and there is a story about a Shisa being awakened to fight a monster (Though, it's a sea dragon instead of a giant robot).
- The original myth is even referenced in the song used to summon/awaken King Caesar. Translated, she's singing "Kill the dragon, King Caesar!".
- Space "X": The aliens boasted that Godzilla could not break Mechagodzilla's armor of space-titanium. Which is clearly superior to Earth titanium, because it's from space.
- Spell My Name with an S: King Caesar, whose name is likely officially romanized that way because most people outside of Japan are unfamiliar with Japanese folklore, particular regional folklore like Okinawa's. In particular, especially at the time of release, not many Westerners knew what a shisa is. Star Maker's blurb also spelled it as "King Seeser", which was common on Toho's own materials at that time. As such, it's probably to avoid having to add extra exposition to an already limited amount of dialog.
- Spot the Imposter: Mechagodzilla first puts on Godzilla's skin so he can frame the true Godzilla for all the rampage he does. Before he could fully deceive humanity, the real Godzilla intercepts him and rips off a huge chunk of the disguise, forcing the Simians to decide that the lie can't continue. Anguirus wasn't fooled by the disguise, as he too broke a piece off, but Mechagodzilla punished him for doing this by brutally breaking his jaw.
- This Cannot Be!: Kuronuma has this reaction when Godzilla and King Caesar finally destroy Mechagodzilla.
- You Have Outlived Your Usefulness: Kuronuma tries steaming Professor Miyajima, his daughter Ikuko and Masahiko to death when Miyajima is done rebuilding Mechagodzilla.