Frightful is a female peregrine falcon and the novel’s protagonist. The novel is narrated from a limited third-person point of view, which provides insight into Frightful’s thoughts and instincts. Frightful is an unusual protagonist in that she has neither dialogue nor even internal monologue, yet George still employs various techniques to create indirect characterization and offer a sense of the falcon’s interior life and personality. Through the narration’s vivid sensory descriptions, readers can gain understanding of how Frightful perceives the world around her. Her interactions with Sam, as well as her responses to his presence or absence, also reveal her relational quality. However, while she is typically gentle and loving toward Sam, she is also a formidable hunter. She is agile and strong, with wide shoulders and a tapered body. Her shiny legs, dark eyes, and black beak make her a fierce and beautiful bird.

Even in the trilogy’s earlier novels, one of Frightful’s key traits is her faithfulness, which she demonstrates primarily in her attachment to Sam. Frightful first appears in the opening novel, My Side of the Mountain, as a hatchling whom Sam steals from her nest with the intention of training her to hunt for him.