黑洞第三行星的人对机械哥吉拉进行改良，并且拉拢一位天才科学家真船信三博士，控制恐龙型怪兽泰坦龙来一起毁灭地球，国际刑警组织和哥吉拉将如何对付这个强大的邪恶军团？Aliens from a dying galaxy plan to destroy our cities and build their new home on Earth. Their weapon is Mechagodzilla, a 400-foot-tall robot armed with powerful lasers and guided missiles. Only Godzilla is mighty enough to stop the colossal machine, but when Professor Mafune joins the aliens, not even Godzilla will be able to defeat them. Mafune controls Titanosaurus, a gigantic amphibious dinosaur, through a biochemical connection with his cyborg daughter, Katsura. Godzilla is no match for Titanosaurus and Mechagodzilla together, but Interpol agents have discovered Titanosaurus' weakness, which may give Godzilla the fighting chance he needs to save the world!