If I were to write this piece, I would probably refer to eNote's character description of Boo first, so that I would be able to present a fairly accurate picture of Boo Radley, in Harper Lee's To Kill a Mockingbird. I would include his history, how he watches the children for entertainment, how he comes out only at night, how the children are like the only friends he has had in many years, and how angry he becomes when he sees Bob Ewell trying to harm them. I would include that he has been harmed and that he won't let it happen to Jem and Scout, too. (In your writing, try to imitate the dialect so many people in Maycomb use in sounding like southerners from a small southern town.)
I would start by introducing myself:
My name is Arthur Radley, but most folks just call me Boo. No one knows me too well: most people just make up stories about me, but I guess that's what folks do when they don't really know a body.
The quote I would use to support this is:
Jem gave a reasonable description of Boo: Boo was about six-and-a-half feet tall, judging from his tracks; he dined on raw squirrels and any cats he could catch, that's why his hands were bloodstained—if you ate an animal raw, you could never wash the blood off. There was a long jagged scar that ran across his face; what teeth he had were yellow and rotten; his eyes popped, and he drooled most of the time.
I might also have Boo respond to the rumors which he can hear when he walks around at night and people visit on their porches or talk with their windows open, but I would address only part of the quote: perhaps the part that he doesn't eat animals. He eats what he's given and has learned to be thankful. There is also the rumor that he stabbed his dad with scissors: he could say his father tripped over him while he sat cutting paper on the floor, and his mother thought Boo did it.
You could describe how Boo leaves gifts in the tree, and how exciting it is to see the kids collect them and wonder about them; you might also speak about the night the kids sneak over into the Radley yard and the consequences (including finding and sewing Jem's pants); you could talk about covering Scout with a blanket during Miss Maudie's fire; and, I would mention how Boo watches around the window shades when the children play, like when Jem smacked the side of the house, and Scout's tire rolled into the yard and hit the side of the house, which made him laugh. Mostly importantly, I would write about how he follows the kids the night of the pageant, how funny Scout's costume is, and how he becomes frightened and angry when he sees Bob Ewell attack the children. Include a comment on how the Sheriff (Heck Tate) decides to say Ewell fell on his knife, and how Boo is glad because he wouldn't want people coming around to his house to talk to him, even if Nathan let him, which he probably wouldn't.
Offer your own personal responses as Boo's reactions because your writing will sound more realistic. We can only imagine how hard life has been for Boo, but he is still our unlikely hero at the end of the story. He can lastly speak about loving the kids, knowing he will miss them when they grow up and move away.
This is how I would handle the assignment if I were writing it.