Hedorah is a monster made when some alien ectoplasm feeds on the filthy pollution created by the plants and factories of industrial Japan. Hedorah secretes burning poison, blows out choking gas and covers its victims in radioactive sludge. It's touch is deadly, it's very presence threatens the world, and we have only ourselves to blame.
Hedorah is notable for its one red eye, which stares back at mankind in disgust, like a smoking beagle or a rabbit having shampoo squirted in its face. That eye, that single eye: damaged, bloodshot, angry, defiant, accusatory. We can't stand that eye, as we know that we created it. We know that it looks right through us. Godzilla will eventually destroy Hedorah, of course, closing that offending eye for good in a maelstrom of electricity and death and tearing apart.
Before Godzilla lumbers back home, however, he will turn and stare down at the humans who have cooked up this catastrophe, the same humans whose meddling with the atom made him. His look of withering contempt is a judgement on us all.