This work is titled "Loose Ends"
Okay, fair warning, this turned down a dark path, with really tragic implications, but it’s a topic not often brought up.
What happened to Quasimodo’s father?
Well, it might not need saying, because the obvious and probable answer is not a happy one. Presumably, he was taken to the Palace of Justice and executed along with the others on that boat some time later. This man in the end was responsible for ending both of the parent's lives.
It just made me wonder, did Frollo have any further contact or interaction with him, however brief during that time? Did he know? Did he dare disclose the fate of his wife and child?
In any-case, likely ordered his execution anyway as quickly as possible. No ties, no witnesses- other than the archdeacon.
And yes, in my opinion, I do personally believe he is Quasi's father, and so is the mother (I have heard theories he may not be/ had been adopted, etc.), but I don't think it is the case in Disney's 1996 animated version; there's nothing in the movie to suggest that. Yes, the book (with all the baby swapping -best not to indulge in that stereotype-yesh!) and the stage show are another matter and go their own ways. Related, but separate entities,
'"Quasi doesn't look like his parents." That’s most likely related to whatever genes he inherited that caused his disfigurement, inheriting mutated/ latent or recessive genes etc. Genetics are weird, really weird sometimes, over multiple generations, nothing can be ruled out. Genetic suppressive traits -such as ginger hair, paler skin can crop up generations later, making it possible that people without any physical qualities of the genes still bare a child that has it. (Do your punnett squares, people)
The biological relationship is stated in the film's narrative and are officially credited as Quasimodo's parents. At least his mother is. There is no official confirmation of him being adopted from writers, Tab Murphy or the production team. The Director's commentary confirms this too.
The whole Bells of Notre Dame sequence was done in the way it was in order to *simplify and streamline the story from the more convoluted original tale- adding in such a complication seems absurd and unlikely. *Reference: Gary Trousdale mentions it here in this video interview. [Link CLICK HERE]
Him using the words 'shut it up will you' - again, this is not sound evidence to suggest he wasn't. It may have been because of the tense circumstances of their situation at the time.
Finally, (though it may not count as canon, but is worth mentioning as it may the best to go on) In one of the series of officially licensed Disney story books called 'Quasimodo the Brave' it states that they are his parents, and the reason that they journeyed from Orléans to Paris, was to get medical help for their child. And it goes even darker and more far-reaching- afterwards Frollo, furious of their entry to Paris, even ordered the round up of all the Romani in Orleans too. Yikes!
Frollo really is a bastard, isn't he?
I also wrote a little story to go with this picture. Click here