Gamera The Giant Monster vs. The Ice Men From Outer Space

Gamera The Giant Monster vs. The Ice Men From Outer Space (大怪獣ガメラ対宇宙氷人, Daikaijū Gamera tai Uchū Kōri Hito) is an unmade 1966 tokusatsu film which would have been created by Daiei Film Company Ltd.

History
Gamera The Giant Monster vs. The Ice Men From Outer Space was planned to be a sequel to the original Gamera film, set in the middle of an invasion on Earth conducted by ice-based aliens dubbed "The Ice Men". Their invasion begins by setting off multiple volcanic eruptions across the world in an attempt to create a new ice-age, thus causing humanity to migrate underground, and giving the invaders control over the surface. However, the Earth-dwellers do not go underground as planned, and the Ice Men decide to enslave the human-race instead. Luckily, Gamera is freed from his imprisonment in a Mars rocket, and manages to fly back to Earth just in time for the battle between mankind and the invaders who unleash their own towering beast the "Ice Giant".

Trivia

 * The concept of the Ice Giant kaiju would later be adapted into the idea for Daimajin and his first film.