Hedorah originated as a colony of microorganisms that consumed chemical substances in water. It was found in a mine by the Chinese government, and was being experimented on to be used as a biological weapon. It was deployed in Beijing, in 2005 to combat Anguirus and Rodan, to prevent them from destroying the city.
After defeating them it went out of control and destroyed Beijing and Tianjin overnight. It disappeared after consuming all the pollutants in the area.
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