Taiga Aisaka, Gryffindor 6th: She doesn't write enough to get the extra credit, but she makes the required length and it pretty competent. She doesn't really care about trolls, though, and it reads pretty much like a textbook because she isn't really interested. All of her facts are in order, and organized, though.

Lili Rochefort, Slytherin 7th: Dangerous ANYTHING is her area of expertise, so she easily makes the extra credit requirement of 3 feet. She actually goes a little overboard on explaining why they are dangerous and how to combat them, so the section on their habitat is a little skimpy, as Lili figures he's not going to want to read her essay all day long.