An ever evolving alien life-form arrives on a comet from the Dark Gaseous Nebula and proceeds to consume pollution. Spewing mists of sulfuric acid and corrosive sludge, neither humanity nor Godzilla may be able to defeat this toxic menace.
| Actor | Role |
|---|---|
 Akira YamanouchiDr. Toru Yano | Dr. Toru Yano |
 Hiroyuki KawaseKen Yano | Ken Yano |
 Toshie KimuraToshie Yano | Toshie Yano |
 Keiko MariMiki Fujiyama | Miki Fujiyama |
 Toshio ShibaYukio Keuchi | Yukio Keuchi |
 Yoshio YoshidaGohei - fisherman | Gohei - fisherman |
 Haruo SuzukiJSDF Officer | JSDF Officer |
| KKentaro WatanabeAnnouncer B | Announcer B |
| YYukihiko GondōMean General | Mean General |
| EEisaburo KomatsuFisherman | Fisherman |
 Tadashi OkabeScientist | Scientist |
 Wataru ŌmaeHelpless Police Officer | Helpless Police Officer |
| SSusumu OkabeInterviewer | Interviewer |
 Haruo NakajimaGodzilla | Godzilla |
 Kenpachirō SatsumaHedorah (as Kengo Nakayama) | Hedorah (as Kengo Nakayama) |
| YYoshio KatsubeJSDF Engineer | JSDF Engineer |
| TTakuya YukiCorrespondent | Correspondent |
| TTatsuhito GoYouth | Youth |