Reigon: Devil of the Seabed (海底の魔王レイゴン
Kaitei no maō Reigon?) is an unmade 1966 Nikkatsu film.
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 kaiju ideas.
Planning was done by Hideo Kodama, the draft was written by Shun'ichi Yukimuro and Ryuzo Nakanishi.
A giant manta ray dubbed "Reigon" appears one day and wreaks havoc across the world--and then fights a giant iguana.