Tolly is a seventeen-year-old high school student who works part-time at his mother's hardware store in Lamesa, Texas. Grieving the recent loss of his father in an oil rig accident, he struggles with social isolation and is widely viewed by his peers as fragile due to a severe peanut allergy. After a cruel hazing incident at a local party, he begins unwillingly taking on the physical attributes of a movie slasher, forcing him to reckon with his intense resentment toward the classmates who bullied him.

Amber is an Indigenous American high school student and Tolly's fiercely loyal best friend. An aficionado of horror films—a passion she shares with her military brother—she quickly realizes that the horrific events in Lamesa are following strict cinematic rules. She acts as a tactical advisor, attempting to predict and counter the emerging threat by analyzing popular slasher tropes while facing local prejudice from town authorities.

Justin was an intensely unpopular boy whose desperation for peer approval led to a fatal accident on a pumpjack during an initiation ritual. He returns from the grave seeking brutal retribution against the clique that caused his death. His violent rampage sets the standard for the supernatural events that follow and acts as a grim cautionary tale for Tolly.

Mel is a baton twirler in the high school marching band and an active participant in the town's social hierarchy. Quick to anger, she retaliates aggressively against perceived slights. She organizes the severe hazing ritual that triggers Tolly's life-threatening allergic reaction, fleeing the scene rather than facing the consequences.

Stace is a level-headed high school student who occupies a secure rung on the social ladder. Despite her association with popular cliques, she retains a strong moral compass and quick reflexes in emergencies. She frequently steps into danger to administer first aid or fend off attackers, fitting the classic cinematic archetype of the resourceful survivor.

Sheriff Burke is the first female sheriff in the county, tasked with investigating the sudden explosion of violence in Lamesa. She approaches police work with a rigid, suspicion-heavy mindset. Her investigations are clouded by her overt racism against Indigenous Americans, leading her to dismiss or suspect certain residents unfairly while trying to maintain order.

Deek is a high school alumnus and former leader of the Future Farmers of America team. His desire for dominance and reckless peer pressure directly caused the initiation accident that killed Justin. He uses his status to manipulate others, fleeing instantly when the consequences of his past actions violently return to his doorstep.

A former high school flag girl who purchased the local hardware store using a loan after her own mother's death. The sudden loss of her husband has left her highly protective of Tolly, fearing she will lose her only remaining family member. She maintains a quiet routine of renting movies with her son to preserve a sense of normalcy in their grieving household.

Lesley is a member of the high school marching band who actively participates in tying Tolly down and forcing him to ingest peanuts. Despite local rumors about his sexuality, he conforms to peer pressure and cinematic genre expectations, engaging in reckless behavior at the Fireworks Camper that makes him a prime target for supernatural retribution.

Shannon is a marching band student who claims voluntary celibacy but breaks her own rules during a secret rendezvous at the Fireworks Camper. She shares culpability in Tolly's near-fatal hazing, laughing along with the group rather than intervening to stop the cruelty.

Bo is a local welder who previously worked alongside Tolly's father on the oil rigs. He observes the deteriorating situation in town with an outsider's perspective. He extends genuine kindness to Tolly by buying him a soda, representing the compassion and community support that Tolly struggles to accept amid his overwhelming anger.