This film could not be produced due to budget limitations. The Return of King Ghidorah was replaced with Godzilla vs. Gigan, cutting Mogu and Varan (as the latter's suit was still in a poor state after being used in Ultraman), while switching Rodan with Anguirus.
An alien named Miko sends out King Ghidorah, Gigan, and Mogu to destroy Tokyo. But, Godzilla and Rodan intercept them, until the three go off to space. But they return, and Godzilla, Rodan, and Varan send them out to space. Miko would've been killed in the Godzilla Tower by Godzilla.
- Gigan could fire a spiked ball from his right hand.
- The Return of King Ghidorah is also the name of an unmade direct sequel to the 1991 film Godzilla vs. King Ghidorah. Aside from the title, the two films are not related.