Firstly, it is dangerous to discuss these creatures. I don’t believe anyone today knows their nature exactly, but they are known to be more spiritual than man, but less than Melachim who are pure spirit. They have a physical component as well.
As far as the dybbuk, this is some sort of spiritual remnant or gilgul or something of a person who once lived. This is what regards the story of the Chofetz Chaim