Anna is maybe 3/4ths of the way through the book so SHHH NO SPOILERS
  1. Percy Weasley
    Because he's always lurking by the girls' bathrooms. Really, like, all the dark corners. And he spent the whole summer up in his room. And he's so grumpy.
  2. Gilderoy Lockhart
    Maybe thought he could handle the monster because he's always hanging out with monsters in his books. Then, the monster put a curse on him, and now he's hypnotized to be on the monster's side.
  3. Lucious Malfoy
    Because he's evil and he probably framed Hagrid for opening the chamber fifty years ago.
  4. Severus Snape
    He also just has that evil tone about him.