THE RETURN OF KING GHIDORAH
Extraterrestrials hailing for Nebula Space Hunter M begin a slow conquest of Earth, stealing identities and building a base of operations from a giant Godzilla Tower. Their ultimate plan of action is to decimate the Earth and then rule the remains. The Nebula Space Hunter M aliens scheme to use King Ghidorah, Gigan and the monster Mogu to accomplish their goal by controlling the creatures from action tapes. Due to the interference of humans, the tapes accidentally summon Godzilla, Rodan and Varan to the area, who in turn face off against the three space monsters for the fate of Earth.
This project was an early, more extravagant version of what would ultimately become Godzilla vs. Gigan (1972). Despite the similar plot to what the movie became, the original concept had a rather large monster cast. On the alien side, King Ghidorah was touted as the project's character to beat, unlike the final draft which placed greater focus on Gigan. The cyborg monster was also fairly different at this stage, still having a scythe-like hand, but also a spiked ball and chain on the other. They were to work alongside another new monster called Mogu, a flying beast that could fire an oral weapon from its maw.
On Earth's side, Godzilla, Rodan and Varan were to face off against the invaders. All three monsters had helmed their own films, while Godzilla and Rodan's marquee value was already well known.
Unfortunately, the project's budget was ultimately far too modest for the idea's in this early script. At the minimum, it would have required three new suits in the form of Gigan, Mogu and Varan, the latter of which only had a small prop used for it in Destroy All Monsters (1968). Taking the budget under consideration, Mogu was dropped while Rodan and Varan were replaced by Anguirus, to take advantage of the new suit that had been created in 1968 for the monster. King Ghidorah's name was dropped from the title, and the film became Earth Destruction Directive: Godzilla vs. Gigan.
Source: Toho Kingdom