Follows the heroic efforts of the crypto-zoological agency Monarch as its members face off against a battery of god-sized monsters, including the mighty Godzilla, who collides with Mothra, Rodan, and his ultimate nemesis, the three-headed King Ghidorah. When these ancient super-species - thought to be mere myths - rise again, they all vie for supremacy, leaving humanity's very existence hanging in the balance.
The U.N.G.C.C. (United Nations Godzilla Countermeasure Center) recovers the remains of Mecha-King Ghidorah and construct Mechagodzilla as a countermeasure against the nuclear menace. Meanwhile, a giant egg is discovered alongside a new monster called Rodan. The egg is found to be an infant Godzillasaurus just as Godzilla emerges once more.