Haruo Sakaki: “Even though we defeated it, what was it really? How was it able to live for 20,000 years?”

Martin Lazzari: “This is just my opinion, but I think this is a different Godzilla than the one that drove us from Earth.”

Haruo Sakaki: “But its appearance and abilities were almost identical.”

Martin Lazzari: “And that's exactly why. Life's true nature is found in change. No matter how gradual the renewal cycle may be, it's impossible to maintain the exact same appearance. So this one may be an offspring that inherited Godzilla's form and nature. Such a guess would actually be the most natural. Although the question remains of why there was only this one.”

― Haruo Sakaki and Martin Lazzari discuss the identity of Godzilla Filius after he is defeated. (GODZILLA: Planet of the Monsters)

Formed from cells that divided from Godzilla Earth during the 20,000 years he ruled over the Earth, Godzilla Filius grew to a height of 50 meters and was living in the former Tanzawa area when the Aratrum returned to Earth to reclaim it. Mistaking Filius for Godzilla himself, Haruo Sakaki and the Aratrum crew undertook a desperate plan to exploit Filius' only weakness and destroy him. While Haruo's plan was successful in destroying Filius, he and his allies were caught completely off guard when Godzilla Earth emerged to challenge them.