A good thesis is going to make an argument. That's the point of a thesis. It can't be a statement of fact, because then there is nothing for the paper to argue for and support. The thesis statement will guide the rest of the paper's argument. For a lot of literature, a thesis that forces the paper into a close examination of a character or theme is a good place to start. With The Hobbit you could have a thesis that closely examines Bilbo as a hero character. For example, "Although Bilbo is not initially an ideal hero character, he absolutely becomes worthy of the hero title." This thesis format is a solid format because it allows you to discuss both sides of the issue. You are forced into discussing how and why Bilbo is not a good hero. The next part of the paper will then be why that initial argument is flawed. If you want to examine a theme instead, there's a lot to choose from. You could focus your thesis on Bilbo's courage or how loyalty is observed or not observed by certain groups of characters within the story.