
San Francisco is threatened as a bizarre, quadrapedal multi-colored subterranean monster appears underneath the city. The creature is called the Eartheater, since it lives by devouring huge amounts of rock, soil, and steel, wreaking much havoc in the process by causing buildings and other man-made structures to collapse; the Eartheater also projects waves of sonic force from two antennae on top of its head to help it dig, but which can also be utilized as a formidable weapon in battle. As the crew of the Calico travel into the underground tunnels created by the Eartheater to investigate, they're trapped by the creature. Calling on Godzilla for assistance, the Big G rescues the Calico crew and drives the Eartheater above ground during the ensuing battle. As the earth-devouring monster climbs the Golden Gate Bridge to escape, Godzilla knocks the creature off of the structure with his laser beams. Landing in the water, the Eartheater discovers his fatal weakness as he dissolves into mu
As a long dormant volcano in Alaska suddenly erupts, the crew of the Calico decides to investigate the phenomena. Suddenly, an enormous winged creature called the Firebird, since she literally thrives in super-heated lava and breathes fire, emerges from her resting place in the volcano (there is actually a legendary avian creature by that name in Russian mythology, though this fact is not alluded to in the show). The Firebird flies across the frozen Arctic Sea to find a place to spawn, the heat from her body causing huge floods as her very proximity melts glaciers. Godzilla is called to the rescue by his human friends, and after a fierce battle, he defeats the Firebird by trapping her in an undersea cave
As the Calico investigates a strange electromagnetic power source beneath the sea near the Bali Trench, an oil tanker is sunk by what appears to be a bolt of lightening that originates underwater. As Dr. Darian, Brock, and Godzooky travel underwater in the bathysphere, they are attacked by the source of the lightening bolt, the Megavolt Monster, an aquatic kaiju that resembles a giant electric eel. The monster severs the bathysphere's umbilical cord, and the craft ends up landing on an underwater desert that's protected by an air bubble. There the trio discovers an entire colony of Megavolt Monsters who acquire their electrical power by feeding off an electrolyzed outcropping of stone, which appears to be the mysterious power source that the crew first investigated. After battling the first Megavolt Monster to a standstill to save the Calico, Godzilla arrives at the underwater desert to save the bathysphere crew, and he penetrates the air bubble, causing the sea to rush in and de