The thorny Mrs. Coulter is one of the primary villains of the His Dark Materials series, and she's very much influenced by the social and theological debates that drive the world of both the HBO adaptation and the books. One of the biggest yet not explicitly answered questions about Mrs. Coulter is why does she hate her daemon so much? The answer can be figured out by simply studying the character.
In the primary world shown in the series, humans are accompanied by daemons: externalized manifestations of their souls that present as animals. Typically, daemons are the opposite gender of the person (the series assumes gender is binary), so Mrs. Coulter's daemon is male. When the person is young, their daemon might shift between different animal forms, but when they reach maturity (puberty) they settle as a specific animal that represents an aspect of the human's personality. A person doesn't touch another's daemon, although daemons sometimes interact. And daemons and their human typically can't be far apart -- because they feel each other's pain. Pain is a major reason for the negative relationship between Mrs. Coulter and her daemon.
Why Is Mrs. Coulter So Mean to Her Daemon?
There are people in His Dark Materials' strictly theocratic world who believe that humans' tendency to sin correlates to them being surrounded by something called Dust, which is known in the "real" world as dark matter. Dust surrounds adults with their settled daemons, but does not stick to children, whose daemons are still shifting. This is what leads Mrs. Coulter (played by former Luther antagonist Ruth Wilson) to pursue her initial goal of separating children from their daemons: she genuinely believes this will keep them from being exposed to Dust (sin). Early experiments result in the children dying or becoming empty shells of themselves, but Mrs. Coulter perseveres.
She hasn't attempted this procedure on herself or any other adults (who are already exposed to sin), but her relationship with her own daemon is certainly complicated. Her daemon is a beautiful, unnamed golden monkey who knows how to appear flattering and friendly when necessary. However, it behaves cruelly -- especially when provoked.
Mrs. Coulter often berates and abuses her daemon; she sometimes goes far enough from him to cause them both pain. She also makes her daemon fight other daemons on her behalf. All of this is very unlike how most people -- even other, more superior members of the theocracy -- interact with their daemons. Daemons such as Lord Asriel's Stelmaria have a much less contentious relationship with their humans.
She clearly hates her daemon -- or at least has conflicted, negative feelings towards him -- despite him being an extension of herself. Therefore viewers can infer that Mrs. Coulter hates her daemon because she hates herself. She causes her daemon pain and experiences pain herself. She berates her daemon because she can't effectively berate herself. She controls her daemon because she wants to control herself. But more often than not, her daemon acts up, exposing both himself and Mrs. Coulter as erratic and malicious.
His Dark Materials concluded in December 2022. The complete series is available to stream on HBO Max.