Ever since he appeared, everyone has been shouting that he could be hilda's father and if not than her uncle, but i actually think he could be hilda's grandfather. The main reason why i think this is because he looks way too old to be a dad because of how young johanna is compared to him, this is even shown more given that we actually see a younger johanna and if johanna looked like that when hilda was 5-6, then how old would've the bell keeper been, given his already aging appearance in the present. The bell keeper would've already been middle age if johanna was that young in the deerfox. Plus i think he had more grandfather energy than father energy. Heck he might not even be a granddad but a granddad in law. what do you think?