What is frightening to the children about the Radley house?

The Radley house is said to contain a "malevolent phantom" by the name of Boo Radley. Though the children have never seen him, rumors abound that he is over six feet tall, has rotten yellow teeth, popping eyes and a drool, and eats raw animals. Whenever strange things happen in the neighborhood, Boo is often blamed. Boo's story is an extension of the strange Radley family, who have always disregarded local custom by "keeping to themselves."

a malevolent being by the name of boo radley who eats raw animals.