Board Thread:Movie Discussions/@comment-3367060-20140814193129/@comment-26155014-20150427151341

Titanollante wrote: I guess it's possible, but I see Rodan-Mothra-Godzilla being reluctant allies against Ghidorah. Like how it was in Ghidorah, the Three-Headed Monster i found an alien origin story that will may be possible (even though i still think they will most likely do an earthling creature).

so:

Ghidorah original was a creature that lived in a planet billions of years ago, but suddenly his planet was destroyed, throwing him in space and smashing it into a meteor that eventually caused the dinosaurs to extinct. but instead of killing it ,Ghidorah  absorbed the meteor's minerals and also from earth radiation- mutating it into a giant monster.

that's the most realistic alien origin story for Ghidorah Legendary will use.