On the island dubbed "Monster Island" due to its inhabitants, the ground exploded open. Two giant drills protruded from the ground. Then, from the soil, Megalon emerged with a shriek. His insect eyes scanned the area in search of his prey. There. He spotted the mutated Ankylosaur called Anguirus relaxing on the beach. He approached him and the animal looked up, sensing danger. Anguirus stood up and roared a challenge at Megalon. The insect spun his drills and roared back. Before Anguirus could move, he was hit in the shoulder with a lightning bolt, getting knocked back. Megalon chirped gleefully and reapproached him, drills spinning. However, Anguirus was not ready to surrender after just one hit. He dove at Megalon and tackled him to the ground, proceeding to savagely bite the bug. Megalon rose a spinning drill in defense and scraped Anguirus' face, forcing the creature to retreat. A small amount of blood dripped from the gash and Megalon got back on his feet.
Before the battle could escalate further a deafening roar was heard from within the island. The loud stomping shook the Earth. Birds flew from the trees. Trees collapsed as something approached. Both monsters were motionless. One hopeful, the other feeling dread. The king was approaching. Godzilla, the king of the monsters had been awakened and had become angered by the return of a foolish invader from decades before. Before Megalon could make a move he was knocked on his back by a blast of cyan atomic fire. The reptilian monster joined the side of his spiked companion, prepared to eliminate the threat to his home.
Anguirus rolled into a ball and hit Megalon, who had just managed to get back on his feet, only to be knocked into a rocky cliff. Godzilla rushed the beetle, ramming his head into the alien's abdomen. Megalon stabbed a drill into Godzilla's gut and activated it. Flesh blood spewed from the wound, making Godzilla bellow in pain. It became evident that Megalon's lust for revenge began to overcome his fear.
Back in 1973 when he was sent to test Godzilla's strength, he had been defeated and treated as a failure since. The reptile had been just as aggressive back then and bathed the insect in nuclear fire. It took Megalon a long time to recover from that encounter and he would rather die than fly back to his master beaten and burned once again.
Godzilla grabbed Megalon's arm and forced out the drill, falling to his knees. He was bleeding from the gaping wound. Anguirus immediately swung his tail into Megalon's legs from behind, and, with a surprised shriek, the creature dropped. Godzilla was up again in a short amount of time. His radioactive cells provided him with a superb healing factor. Megalon opened his mouth and fired a napalm bomb at Anguirus. It exploded and bathed the dinosaur in fire, forcing him to momentarily retreat into the water. Megalon returned his attention to Godzilla and fired lightning from his horn. Godzilla ignored it as he powered up his atomic breath. His spines began to glow bright cyan and light poured from his mouth. The blast of atomic flame fired from his mouth right at Megalon's head. As the fire approached him, Megalon thought that on the bright side he would not have to live to face further humiliation. Then his head exploded into flames that spread to the rest of his body as Godzilla maintained the blast. The blue fire ceased and Megalon's charred remains fell to the ground. As Anguirus rose from the depths, Godzilla roared triumphantly.
Their victory was short-lived, as a group of alien fighters arrived, firing searing bolts of plasma at them. Anguirus lied down and allowed his spiked carapace to take most of the hits while Godzilla tanked the shots and began firing his atomic breath in retaliation. Not a single ship survived the encounter. As the last metallic ball of flame fell from the sky, Godzilla knew something was wrong. His planet, his home, was under attack. He and Anguirus took to the ocean to follow the source of the alien ships. Godzilla did not care for the other lifeforms in this world, but he knew that they had to act now for the sake of their home.