I'm not clear with what you are looking for in terms of advise or approval, since you've stated that this is right out of the gate not a lore friendly character and don't plan on making her one, I guess that helps narrow it down?
I'm aware of Parasyte and I get where you're trying to go with it but I actually feel the removing the head part is borrowing too much and really not necessary for the concept you are trying to work with, plus it leaves too much to explain to those not familiar with the story(which never fully explains the premise itself).
I would say you can drop the specifics while still keeping the idea of what you're trying to manage.
I'm aware of Parasyte and I get where you're trying to go with it but I actually feel the removing the head part is borrowing too much and really not necessary for the concept you are trying to work with, plus it leaves too much to explain to those not familiar with the story(which never fully explains the premise itself).
I would say you can drop the specifics while still keeping the idea of what you're trying to manage.
