Who is Boo Radley, what do they say about him, and why are they fascinated with him?

Arthur "Boo" Radley is the Finch family's reclusive neighbor, who rarely leaves his home and is the unfortunate subject of many rumors throughout the community. Towards the beginning of the novel, the children fear Boo Radley and view him as a "malevolent phantom." Dill and Jem are particularly obsessed with Boo after hearing the numerous rumors that surround their enigmatic neighbor. Miss Stephanie is the source of many of these rumors surrounding Boo, which portray him in a negative light.
Jem, with his fantastical imagination, conjures the image that Boo is a six-and-a-half-foot-tall creature, who dines on raw squirrels and has a jagged scar running down his face. Since Boo is never seen throughout the neighborhood, Jem and Dill's imaginations run wild as they continue to elaborate on their neighbor's mysterious identity and life.
The fact that the Radley family is reclusive and live in a dilapidated home intrigues the curious children, who become fascinated with the idea of getting Boo to come out of the house. As the novel progresses, the children mature and eventually view Boo as their compassionate, shy neighbor.