
While diving in the sea near the West Indies, Dr. Darian and Brock are startled when they are attacked by a bizarre mutant life form...a creature composed entirely of seaweed, which continues to grow increasingly larger as the plant beast merges with more and more seaweed. The two divers barely escape the plant creature's two huge tendrils as they frantically swim back to the Calico. There they call upon Godzilla to deal with the creature, and while the Seaweed Monster is no match for Godzilla, the Kaiju King can't seem to severely injure the plant creature's physical substance. As the Seaweed Monster menaces a nearby inhabited island, Dr. Darian notices that a severed piece of the creature completely dried up after excessive exposure to sunlight. Thus, she directs Godzilla to drag the Seaweed Monster onto land, where the searing tropical sunlight eventually causes the plant creature to wither and die.
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