Mia is a young, energetic fox kit raised in a loving family in the Eavey Wood. She is resourceful, fiercely loyal, and guided by a strong moral compass instilled by her mother and teacher. When a sudden outbreak of the "yellow sickness" forces her out of her home territory, she must quickly adapt to survive in the dangerous, wider world.

Uly is a gentle young fox born with an underdeveloped, shriveled foreleg. Scorned by his sisters and burdened by his physical disability, he struggles with extreme anxiety and low self-esteem. Despite his fears, he possesses a strong instinct to protect those he cares about and a deep desire for a supportive family.

Mr. Scratch, who also goes by Wynn, is a sadistic and manipulative adult fox who rules an area he calls the Lilac Kingdom. He completely lacks empathy, governing through fear and viewing any other male foxes as direct threats to his dominance. He enjoys inflicting psychological trauma and expects absolute submission from the vixens he controls.

Miss Potter is an older human woman living in a cottage near the woods. Though she outwardly appears as a fussy, frivolous lady, she is a callous amateur naturalist who traps woodland animals. She experiments on and sketches her captives with a disturbing indifference to their suffering.

Mercy is a vixen trying to raise a large litter of kits on her own after escaping a tyrannical mate. She is gentle and attempts to teach her children compassion, taking special care to encourage Uly despite his physical limitations. Her efforts to protect her family are severely tested by the arrival of a dangerous figure from her past.

A loving and practical vixen who raises her kits in the Eavey Wood. She represents the stoic pragmatism of the animal world, prioritizing the survival of the next generation. When disaster strikes, she is forced to make agonizing decisions to ensure at least one of her children can reach safety.

A trusted and highly skilled teacher to the kits of Eavey Wood. She instructs young foxes on hunting, avoiding predators, and interpreting their environment. Her sudden contraction of the "yellow sickness" turns her from a beloved mentor into an immediate, terrifying threat.

One of Mia's brothers. Having lived a sheltered and safe life, he initially struggles to grasp the reality of their teacher's sudden illness, attempting to frame the terrifying situation as a simple teaching exercise.

Another of Mia's brothers who attends Miss Vix's lessons. He relies entirely on the safety and stability of his family unit before disaster abruptly strikes the Eavey Wood.

Mia's sister. She is the first to notice the putrid stench and erratic behavior of their brother Alfie, serving as the bearer of bad news to her arriving siblings.

One of Mia's brothers. His inadvertent contraction of the "yellow sickness" triggers the central tragedy that destroys his family's peaceful existence.

Uly's sister, known for being the "clever one." She spearheads the bullying against her disabled brother, easily adopting the cruel mentality secretly encouraged by their dangerous father.

One of Uly's sisters. Like her siblings, she adopts a cruel and dismissive attitude toward her disabled brother, viewing him as a burden.

One of Uly's sisters who participates in the collective mistreatment of him, reflecting the hostile environment cultivated by her sibling Ava.

Another of Uly's sisters, sharing her littermates' contempt for their only brother and refusing to help him survive.

One of Uly's sisters. She fully embraces the belief that the scarcity of resources justifies abandoning the weakest members of their family.

One of Uly's sisters. She becomes an unfortunate victim of Mr. Scratch's violence when he uses her to terrorize Mercy into submission.

A timid and anxious vixen held captive by Mr. Scratch. She has been thoroughly broken by his psychological and physical abuse, even believing she should be flattered by his controlling attention.

A male cottontail rabbit who has lost his mate to Miss Potter's cruelty. He gently explains the grim reality of their situation to the terrified Mia, offering a bleak but honest perspective on their captor.