Donna Trenton is the protagonist in Cujo. She dominates the novel’s narration and has one of the richest character arcs, including one directly tied to the antagonist, Cujo. Donna is Vic Trenton’s wife and Tad’s mother. Before the events of the novel, the family moved to Castle Rock, Maine from New York City after Vic started his own advertising company, Ad Worx. Donna became increasingly frustrated trying to adjust to the new small-town lifestyle and her husband’s immersion in his new venture. She began to fear that she was losing her agency and that her inevitable fate was to become another Castle Rock “housewife.” In a desperate attempt to prove her free will, Donna cheated on Vic with a local artist named Steve Kemp.

As the novel begins, Donna is consumed with guilt over her infidelity, causing her to confront her inner conflict about individual agency. This inner conflict is the core of Donna’s character arc and informs many of the decisions she makes throughout the novel. She’s consistently fueled by coming into her own person and embracing her role as an active woman in control of her life while still balancing her family commitments.