Reigon: Devil of the Seabed

Reigon: Devil of the Seabed 海底の魔王レイゴン (Kaitei no maō Reigon) is an unmade 1966 Nikkatsu film.

History
Reigon was the fourth and final unmade film in a series of concepts Nikkatsu Company had before making Gappa.

Reigon got the furthest into the development out of the four scrapped projects, receiving a plot synopsis, speculative screenplay, and ideas.

Plot
A giant manta ray dubbed "Reigon" appears one day and wreaks havoc across the world--and then fights a giant iguana.