The final battle in Godzilla vs. Kong proves that King Ghidorah - and not Mechagodzilla or Kong - will always be Godzilla's greatest enemy.

Godzilla vs. Kong’s final battle proves that King Ghidorah – not Mechagodzilla – will always be Godzilla’s greatest villain. The three-headed monster was killed at the end of Godzilla: King of the Monsters, but the fourth installment in Legendary’s MonsterVerse still found a way to make use of him. During King of the Monsters’ post-credits scene, a potential return for Ghidorah was set up by the reveal his severed head from the Mexico fight was preserved and acquired by Jonah (Charles Dance).

This tease was addressed during Godzilla vs. Kong’s “Team Godzilla” story. While sneaking around an APEX facility, Madison (Millie Bobby Brown), Bernie (Brian Tyree Henry), and Josh (Julian Dennison) stumbled upon the creature’s skull. It was hooked up to wires and being used to power APEX’s robotic Titan, Mechagodzilla. After being infused with the Hollow Earth energy source, Mechagodzilla gained a mind of his own and killed the person controlling him, Ren Serizawa (Shun Oguri).

How it’s possible for a robot to gain sentience can be explained by Ghidorah’s role in his creation. The immense level of power the energy source gave Mechagodzilla effectively rebooted Ghidorah’s consciousness within the robot. This enabled Ghidorah’s mind to take the reins of Mechagodzilla for the final battle with Godzilla and Kong. So while Godzilla was trading blows with Mechagodzilla, the one giving him that vicious beating was actually his old rival. Ghidorah being the secret antagonist of Godzilla vs. Kong reinforces the notion that he’s the most important villain in the Godzilla franchise.

Since Mechagodzilla’s MonsterVerse debut was first leaked in January 2020, there was a lot of anticipation surrounding his mysterious role. Godzilla had already fought one of his biggest villains in the MonsterVerse, so viewers were looking forward to seeing Mechagodzilla take the spotlight in Godzilla vs. Kong. While that ultimately did happen, the movie also offered a fun twist by having Ghidorah take him over. In a way, Ghidorah was able to serve as Godzilla’s biggest threat in not one, but two MonsterVerse movies. Also, it could be that Godzilla knew all along that Mechagodzilla was a vessel for Ghidorah's return since it was his Titan frequency Godzilla seemed to be sensing.

Ghidorah re-emerging in Godzilla vs. Kong and using Mechagodzilla as a weapon against him just goes to show that Monster Zero – a villain who has fought Godzilla on the big screen more than any other kaiju – truly has earned his reputation as the King of the Monsters’ archnemesis. Not only does he have this image in Toho’s movies, but it’s also true for the MonsterVerse as well. Godzilla, who had to defeat Ghidorah thousands of years ago, had to save the world from him again in King of the Monsters and nearly failed. It took a sacrifice from Mothra to finally bring him down. And apparently, that wasn’t even the end of him. Because of his regenerative capabilities, if any part of Ghidorah survived Mechagodzilla’s destruction in Godzilla vs. Kong, there’s always a chance he could come back in one form or another.

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