I would choose Phantom. We have seen many sides of him so far, he can be creepy af sometimes (he makes the throat slit movement sometimes. But then again, he can be sexy during Mummy Dust and then he is doing silly dances during Dance Macabre).
Swiss would also be a good choice, dude stares and smiles at people in a creepy way (except for when he’s dancing with Aurora haha).
You could also choose to write about a made up ghoul. I would still read it, but i do think that some people might not read it bc they prefer to read stories about their favorite ghoul. So that depends on if you care more about your work or the number of reads you get on it.
Just choose what feels right for you!