Mothra II: Arrival of Ghidorah (モスラII：ギドラの到着, Mosura II: Gidora no tōchaku) is the ninth installment of the Godzilla Sagaverse. While it doesn't feature Godzilla, its contents tie into the Sagaverse. In the film, the Shobijin of Infant island summon the gigantic moth deity Mothra to battle an evil, demonic three-headed beast. It was followed by Godzilla vs. King Ghidorah.
Over 13,000 years ago, two alien monsters (Ghidorah, a big and powerful three-headed dragon, and Gigan, a destructive, red-eyed Cyclops) descend upon Earth to wipe out all life. However, the three guardian monsters Mothra, Baragon, and King Caesar awaken to stop the space aliens.
- Mothra: The Guardian of the Earth and titular protagonist, Mothra is a divine moth-like deity who aids Baragon and King Caesar in the battle with both King Ghidorah and Gigan.
- Baragon: The God of Earth, Baragon is a small, ancient, fire-breathing, red subterranean dinosaur reptile that aids Mothra and King Caesar in fights the two invaders.
- King Caesar: The Guardian Monster of Okinawa, King Caesar is an ancient lion-like creature who helps Mothra and Baragon fight against the alien monsters.
- Ghidorah: The King of Terror and the antagonist, Ghidorah is an extraterrestrial three-headed dragon who has come to wipe out life on Earth.
- Gigan: The Cyborg of the Century, Gigan is an extraterrestrial cybernetic creature with bladed arms and a buzz saw in its chest that comes to Earth with Ghidorah.