Hedorah, also known as the Smog Monster, is an antagonist in the Godzilla franchise. This monstrous creature made its debut in the 1971 film 'Godzilla vs. Hedorah' and is depicted as an alien lifeform that feeds on pollution. As it consumes more pollution, Hedorah grows in size and strength, posing a significant threat to humanity and the environment. Its ability to transform into different states, such as gas, liquid, and solid, makes it a formidable foe for Godzilla, who must stop its rampage to save the Earth.