Gyaos's History
An ancient creature awoken by a pattern of unusual volcanic activity across Japan, Gyaos emerged from a large cavern in the mountains of Shizuoka Prefecture, first making his presence known after he attacked and killed a team of geologists by slicing their helicopter in half with his Supersonic Scalpel. Gyaos then continued to menace a nearby village and feasted on blood, principally that of livestock and humans.
Soon, Gamera confronted Gyaos, and after a battle in which Gamera’s arm was seriously damaged by Gyaos’s Supersonic Scalpel, Gyaos fled while Gamera slept in the ocean to recover from his injuries. It was soon learned that light caused Gyaos' skin to shrink, so the light of the city stadium of Nagoya kept Gyaos at bay. Gamera soon returned to finish Gyaos off and, after a battle in the air, Gyaos cut off two of his toes to free himself from Gamera's grasp and escape. Later that morning, two local fishermen discovered Gyaos's toes, which had started to shrink under the effects of ultraviolet light from the sun
Returning to Shizuoka, a complex plan was put in place by the JSDF and the scientists, involving artificial blood and a rotating platform atop a hotel. It was hoped that by luring Gyaos to the blood, then rotating the platform, Gyaos would be dazed and unable to escape, eventually dying in the morning sun. However, this plan failed when the substation powering the platform overheated. In pain, Gyaos smashed the hotel to pieces, then fired his fog to shroud himself from the sun's light, escaping back to his cave.
Eichi, a local boy from the village, came up with a plan to set the surrounding forest on fire, in the hope that Gamera might be attracted to the flames to fight Gyaos. After Eichi's grandfather conveyed this to the team overseeing the operation against Gyaos, this plan was put into action. That night, the forest was set ablaze, and missiles were shot into the mountain to force Gyaos out. The giant monster put out the fires using his fog, but Gamera arrived just in time to begin the fight.
Though Gyaos's Supersonic Scalpel was unable to cut into Gamera's shell, it made light work of exposed areas of his body, and it seemed at one point as if Gamera was going to die after Gyaos lacerated his limbs and tail with the beam, causing the giant turtle to weaken. After Gyaos repeatedly picked up and hurled Gamera at the ground, Gamera recovered his strength and valiantly fought back, knocking Gyaos down by flying into him, then biting into his neck and shoulder to restrain him. With Gyaos unable to escape, Gamera took to the air, and carried Gyaos to the crater of Mount Fuji, still smoking from its recent eruption. As Gamera pulled Gyaos into the crater, the monster tried one last futile attempt to escape, firing his Supersonic Scalpel as the sun rose, but this attempt was in vain, and Gyaos finally died.
Sometime later, a swarm of silver Space Gyaos had attacked the planet Terra, an undiscovered planet in our solar system, being kept at bay only by the Terrans' guardian monster, Guiron. A Space Gyaos arrived near Guiron and tried to attack with its laser beam, but it was reflected by Guiron's blade-like head, and the beam instead sliced off Space Gyaos' right leg. Space Gyaos flew into the air in order to continue the fight, but in a swooping maneuver Guiron sliced off Space Gyaos' wing. With its prey grounded and immobile, Guiron cut off Space Gyaos' other wing, then decapitated it and sliced it into pieces. Guiron picked up one of the segments and inspected it, deciding that Space Gyaos was not fit to eat, then simply threw the piece aside. After Gamera had killed Guiron, the planet was seemingly abandoned to the Space Gyaos.
The pirate spaceship Zanon would later unleash another Gyaos to destroy humanity, then sent it to prevent Gamera from interfering with its plans to conquer Earth. However, Gamera destroyed Gyaos by dragging it into the crater of a volcano.
