Question

What is the topic of this body paragraph ?

Answer 1

The topic of this body paragraph is that Felix is a horrifying creature.

One should note that this paragraph has a solid topic sentence -- the first sentence of any body paragraph -- which summarizes the main idea. Here, this paragraph's main idea is best explained by the first sentence: "Barnaby's descriptions of Felix paint him as a horrifying creature." 

The rest of the paragraph provides more information about what makes Felix so horrifying.