ok…I think I get it. There is a thing/belief (though I don’t exactly remember where I first heard it from) where spirits can form from a lot of negative emotion. It isn’t like how if a person dies and becomes a ghost for revenge. It is if a major tragedy happens, (a mass murder in a building, common suicide spot) and it happens consistently in the same area, then a spirit can form from said negative energy and feed off of it.

What she is saying is that Snake there became monstrous because it may have absorbed negative energy around it, the fear and rage. But…if it is trapped in the town, where exactly did it pick it up?