This is a continuation / reedit of my earlier blog trying to suggest a possible link between the Kaiju and Lovecraft's Cthulhu Mythos.
To start, I have never been satisfied with the idea that Godzilla was nothing more that a radioactive (and somehow resurrected) dinosaur. That story never seemed good enough to encompass the mythic quality of what many consider, "The King of all Monsters". In the 2014 version of the film the writers suggest what seems to me to be a much more satisfying origin for Godzilla and the other Kaiju. The film goes over this very quickly and without much detail, but the suggestion is that the Kaiju predate the dinosaurs by perhaps millions of years, that they feed off of radioactivity, and do not "eat" in any sense of the word that we would recognize. The filmmakers go on to suggest that as the primordial earth started to cool, and presumably became less radioactive, Godzilla and the other Kaiju went into a dormant state close to the planet's core.
This explanation gives the Kaiju a much more mythic and grand origin; but it also provides an interesting possible link to Lovecraft's Cthulhu Myhtos. My understanding of Lovecraft's elder gods is that they originated in space, that they once controlled the earth, and that they are now in various stages of suspended animation under the earth, the sea, or back in space. Perhaps the Kaiju could be envisioned as related in some way to these elder gods. They could be presented as having developed shortly after the big bang as interstellar organisms that consumed radioactive energy. Slowly they evolved into conscious beings with unique characteristics. Perhaps their interactions even play some role in the overall balance of the universe between creation and entropy. Some Kaiju, like Godzilla, eventually came to rest on a primordial earth.
This is where the Kaiju would diverge dramatically from the Chulhu Mythos. While Lovecraft's creations were manifestly evil and bent on the extinction of all life on earth, the Kaiju are more varied with some even taking on the role of the defenders of humanity. As for Godzilla, I like the characterization of the creature as aloof and uninterested in the affairs of humans. His concerns clearly center around the other Kaiju and his motivations are probably best left undefined.