Gamera vs. Monster X is also called as Gamera tai Daimaju Jaiga, Monsters Invade, Kinkong l'impero dei draghi, Gamera vs. Jiger, Gamera vs. Giger, Gamera gegen Jiggar, el señor del caos, Gamera contra Jiger, Frankensteins Dämon bedroht die Welt。

A giant creature attacks Japan during the World Fair and its up to Gamera to stop it. But the monster injects Gamera with its offspring and a research team must take a craft into Gamera's body to eliminate the parasite.