Treat ran away from her pack because she was afraid of being tied down to one partner her whole life. When the road behind her gets blocked by an avalanche, she is forced to find shelter in a vacant cabin near Frosting, where she is repeatedly harassed by the local rabbits. When Frosting's anti-predator policy is adopted, she begins to get harassed even outside of Frosting, culminating in someone wrecking Mochi's garden just to upset Treat. The poor wolf is devastated after that.
Mochi goes through more than one Break the Cutie moment starting with the second game. She genuinely wants to befriend predators but is met with scorn from her own cousin, who ends up kicking her out of the village. Mochi is miserable for many weeks after that, and just as her mood starts to improve, her garden gets trashed. And just when you think it's finally better, the following chapter has her find out that her presumed dead uncle Mango was alive the whole time and feels like she's been lied to her whole life by her family.
Trick might not be as big a contender as the others but they have their moments. Learning that their master who raised them suddenly disappeared without warning, learning that their best friend suddenly disappeared without warning, and spending many months searching for her by themself, all while facing racial harassment from the various towns they visit. However, despite everything, their smile never fades. This gets worse in Trick Comes Home, where Trick is given focus again. They resolve to try and find their master, discovering his hidden secret of being one of the writers of a controversial book series that forced him to go into hiding, then abandon them to discuss writing an apology with his co-authors. Trick then travels to Krem where they recruited by an animal rights activist group to infiltrate the Chickpea Enchanted Farm and steal an egg. Seeing Trick traumatized by the implication of what happens to the chicken in the facility is disheartening.
Outside the main characters, there's also Danny. Once they apologize to Treat, we find out that they've been having issues with their gender identity thanks to some male rabbits in Frosting, and they seem extremely reluctant to tell Juju about this for some reason. Luckily, this is lessened with them trying out they/them pronouns after talking about it with Chai.
Both Mango and Castella. Mango is injured in an avalanche and forced to go live with wolves, not seeing his family for twenty years. His wife Castella on the other hand, is hopeful he's still alive but still extremely heartbroken over his disappearance.
Treat's parents Cotton and Candy. While they're shown to be optimistic about their daughter disappearing at first, it must've still sting. The seventh chapter adds to this with them finding out about Treat's polyamorous relationship and trying to be supportive despite their conservative views.
Genoise yearning for her old familiar Madeleine is bound to hit close to home to anyone who lost/let go a pet of their own.
Drop is implied to have been living in Wormwood for a while, saving travelers from being eaten by her cult, and being too scared to start her life anew. Luckily, her meeting with Trick convinces her and she moves to the witch town to sell seeds.
Myrrh, Trick's master, becomes this with the revelations in Chapter 8: The result of him trying to provide a broader understanding on witches and animal folk was sparked extreme controversy due to perpetuating harmful beliefs regarding predators and the meat industry. He goes into hiding then adopts Trick, only to be forced to abandon them later when he wanted to write a formal apology for his mistake.
In the beginning, Moxie tries to act evil and predator-like, constantly threatening to eat rabbits despite not having the heart to actually do it. The rest of the series starts showing her more vulnerable side, especially regarding her feelings of inadequacy and her sour relationship with her mother.
Juju is not the nicest nor most tolerable person, but to think about the last time she saw her father, it must've been pretty horrifying for a child to leave him with a wolf then never see him again.
Fennel might seem meanspirited towards Treat in her first appearance, but more light is shed on this in the seventh chapter, showing her to be genuinely sad about Treat leaving her behind.
