The UNGCC constructs Mechani-Kong, a Godzilla counter measure robot built in the likeness of a legendary giant ape. When Godzilla and Mechani-Kong fight, Mechani-Kong manages to inject a probe into Godzilla's body containing scientists. The battle is continued with Godzilla fighting Mechani-Kong on the outside, as well as the inside.

After having to abandon the new Godzilla vs King Kong project, Toho decided to go for the next best thing. Have Godzilla fight King Kong's mechanical double, Mechani-Kong. But Turner was not pleased with the idea, and believed that Mechani-Kong would be the same thing as using Kong. So Turner insitied that Toho would have to pay them for the rights to use it. Toho of course didn't want to pay for the rights to Mechani-Kong; consequently, the project was dropped.

The idea of having Mechani-Kong as Godzilla's rival for Toho's 60th birthday was rather confusing as the monster has not even close to the same type of recongintion as King Ghidorah, King Kong, Mothra, Rodan or even Mechagodzilla. It was probably for the best that this film was not made.