I will give you this. This is why I think you should only be able to pick Zombie at the creation screen. You can have your custom character's backstory be WHATEVER you want it to. If I want to pretend I have 4 players that are a family of undead, that SHOULD be an option.
I do agree simply "CHOOSING" Zombie past the creation screen makes no sense. It should only be acquired through special events if not chosen at the very beginning.