Percy Weasley

Percy Weasley is a fictional character in the Harry Potter series. He is the brother of Ron (Harry's best friend), Ginny, Fred, George, Bill, and Charlie, son of Molly and Arthur.

When we first meet Percy, in Harry Potter and the Philosopher's Stone, he is a prefect, and in Harry Potter and the Prisoner of Azkaban he becomes Head Boy. He is relatively humourless, and thus the butt of many of Fred and George's jokes and pranks.

Warning: Wikipedia contains spoilers.

In Harry Potter and the Chamber of Secrets, he is shown to be behaving in a secretive manner, perhaps as a red herring to lead the reader to believe he is responsible for the opening of the Chamber of Secrets. It later transpires that he secretly has a girlfriend, Penelope Clearwater, a Ravenclaw.