Zombies are ghosts in reverse. A ghost is a soul without a body. A zombie is a body without a soul.
Both are products of the question: “Where did this person’s personhood go?”
Conceptual zombies are real. I’ve seen them and talked with them. To themselves, even, they are instances of a category. When they open their mouths they speak on behalf of the category they are. “As a…” When they address you, they address the category you are. They demand that you respond as addressed.