For James, many of the creatures have a sexual theme to them. While not being arousing by design, there is an uncomfortable erotic nature to them. This plays into the sexual frustration of James no longer having the ability to be with his wife, in almost a mocking way, as to show a shallow view that he might secretly have of her. The only antagonist that does not have this in mind is Pyramid Head, as stated before, being some sort of final punishment of death for James.