Hedorah Acid

Born from Earth's smog, a corrosive alien that dissolves steel and flesh alike.

Hedorah is a unique extraterrestrial entity originating from the Horsehead Nebula, transported to Earth by a comet. Unlike traditional monsters, this amorphous alien feeds exclusively on industrial pollutants, evolving into a poisonous sea monster capable of generating its own sulfuric acid. During the decisive confrontation at Mount Fuji, the creature's acidic nature proves devastating; contact with its body and blood inflicts full-thickness chemical burns on Godzilla, corroding flesh down to the bone and costing the King of Monsters an eye.

Quick Facts

Character: Hedorah
Role: Antagonist; Environmental Horror
First appearance: Godzilla vs. Hedorah (1971)
Origin: Horsehead Nebula

Lore & Background

Hedorah begins as a simple alien tadpole but metamorphoses through distinct stages driven by pollution consumption. Initially a sea monster, it gains the ability to move onto land in an amphibious form to feast on smoke from power stations and other industrial sources. As it absorbs more toxins, it evolves into a flying form and eventually its full, massive state. A critical trait of this creature is its regenerative capability; when pieces of its body are flung off during combat, they crawl back into the sea or ground to grow anew, making Hedorah effectively immortal unless completely eradicated.

Reader's Guide

Hedorah's primary offensive and defensive mechanism is its sulfuric acid, which corrodes any material or biological entity upon contact. Regeneration is a key survival tactic: severed parts do not die but regenerate into new entities. The only proven method of neutralization involves rapid dehydration. In the film's climax, the JSDF utilized massive electrodes to strip Hedorah of moisture, causing its body to split and eventually disintegrate into dust when exposed further to the electrical current.

Did You Know?

Kenpachiro Satsuma, who played Hedorah, was struck with appendicitis while wearing the heavy costume during a publicity interview and had to be rushed to surgery.
The scene where Godzilla uses his atomic breath as a jet to fly was added by director Yoshimitsu Banno, despite producer Tomoyuki Tanaka's initial rejection of such an idea.