I mean, we have no idea what the rest of Ghidorah's kind actually looks like in a single shared timeline, and every alternate design of him usually resides in a different universe. They could have more heads, have more wings, more tails, arms, or different sets of abilities that let them terraform worlds in ways that the Ghidorah we know can't. This idea hasn't really been utilised before.

Until Mothra: Queen of the Monsters released and showed us in issue #3 what a Multi-Ghidorah invasion were to actually look like. With it being so bad that humans had to invest in building a Mechamothra for the first time. And there may be even more Mecha Kaijus fighting off the invasion. We don't fully know for sure.

I honestly believe that a full-scale invasion of King Ghidorah's species would do for a pretty good story. Similar to how the Trilopods invaded Earth in Rulers of Earth and overwhelmed most of Earth's Kaijus until Mechs, King Caesar who can't be biologically copied, and Godzilla learning to trust in others and use his title as King of the Monsters to his advantage to beat them. 

This could force G-Force to develop more Mechs of other Kaijus, use multiple Mechagodzilla models at once, expand their defences into Space and outside the Atmosphere, and force all of Earth's Kaijus to stand together under Godzilla's command. Possibly even have it be revealed that more of Godzilla's race are still alive and were only in hiding the entire time to counter the army (If Toho even allows it of course).

What do you guys think? It doesn't even have to be Ghidorah. Many other Godzilla Villains attacking Earth in the form of an army would work (except Hedorah since there's already a comic showcasing that). I can see an army of Perfect Form Destoroyahs (or even new bigger and stronger forms) working in this idea as well.

What if we got we got a Godzilla movie or comic that showcases what happens if King Ghidorah tried to invade Earth alongside his entire species?