Hermione Granger

She initially appears in the first novel, Harry Potter and the Philosopher's Stone, as a new student on her way to Hogwarts. After Harry and Ron save her from a mountain troll in the girls' toilets, she becomes close friends with them and often uses her quick wit, deft recall, and encyclopedic knowledge to help them. Rowling has stated that Hermione resembles her at a younger age, with her insecurity and fear of failure.

Played by Emma Watson