Prior to the big fight in Godzilla vs. Kong, Gojira chose to send all the Titans back into hibernation, which explains why there weren’t many monsters in the movie. Aside from Godzilla and Kong, the only giant creatures to appear in the film were two Warbats, a Skullcrawler, and of course APEX’s mechanized Titan, Mechagodzilla.
That’s not to say that there aren’t plenty of Titans in the MonsterVerse. In Godzilla: King of the Monsters, Ghidorah awakened more than a dozen mythologically-inspired monsters, including Scylla, Behemoth, and Methuselah. Some, such as Yamata no Orochi and Quetzalcoatl, didn’t appear in the movie itself but were confirmed to be on the loose in King of the Monsters. Ghidorah also woke up a third member of the MUTO species, who are among Godzilla’s oldest foes in the MonsterVerse. These Titans initially served Ghidorah, but they switched their allegiance to Godzilla once they watched their leader die at his hands.
The events of King of the Monsters populated the Earth’s surface with all sorts of new Titans for the MonsterVerse to delve into, but unfortunately, they played no role in Godzilla and Kong’s battle, despite the fact that they could have been of some assistance to their alpha. A Godzilla vs. Kong graphic novel prequel, Godzilla: Dominion, has provided an explanation for why they weren’t around. In the story, Godzilla spent much of his time trying to keep Titans like Scylla, Amhuluk, and Tiamat in line, but in the end, decided to send them back to their resting places. Apparently, controlling the MonsterVerse’s Titans had become an impossible task.
It was explained that Emma and Jonah’s plan had great consequences for the Earth. It would seem that Ghidorah woke up far too many Titans at once. What made this so problematic is that the planet already had limited resources; there just wasn’t enough to sustain such a large number of Titans. As a result, the monsters began fighting each other, and some launched attacks on the humans. For two years, Godzilla tried to keep them from causing trouble, but eventually gave up, having become tired from all the fighting and patrolling.
Though it was certainly disappointing that Godzilla vs. Kong passed up a chance to bring back Rodan and fully explore King of the Monsters’ original Titans, excluding them was understandable. Not only does it make sense that Godzilla would have struggled to keep all the Titans in check, but it would have made it hard for Godzilla’s fight with Kong to work if he had minions around to help him. The Titans needed to be taken off the table in order for a fair fight to happen. However, circumstances may be different in the next Godzilla movie. If a powerful new threat emerges after Godzilla vs. Kong, the alpha can call the Titans out of hibernation and lead them into battle.