Aberforth Dumbledore is Albus Dumbledore's brother and owner of the Hog's Head pub. He appears in the seventh book.
Albus Dumbledore is the headmaster of Hogwarts, founder of the Order of the Phoenix, Order of Merlin First Class, Supreme Mugwump of the International Confederation of Wizards, and Chief Warlock of the Wizengamot. He is the only wizard Voldemort fears. He defeated the dark wizard Gellert.
Arthur Weasley is the patriarch of the Weasley family. He works for the Ministry of Magic in the Misuse of Muggle Artifacts Office and the Office for the Detection and Confiscation of Counterfeit Defensive Spells and Protective Objects. He is a member of the Order of the Phoenix. Read more about Arthur
Bill Weasley is the son of Arthur and Molly Weasley. He is head boy of Gryffindor and Prefect. He becomes Fleur Delacor's husband as well as a Gringotts employee and member of the Order of the Phoenix. Read more about Bill
Cedric Diggory is a Hufflepuff student one year ahead of Harry. He dates Cho Chang and is Hufflepuff's Quidditch Seeker and captain as well as a Prefect. He competes with Harry in the Tri-Wizard Tournament. Read more about Cedric
Charlie Weasley is the son of Arthur and Molly Weasley and works with dragons in Romania. He is a member of the Order of the Phoenix. Read more about Charlie
Dean Thomas is a Gryffindor student in the same grade as Harry. He is a member of Dumbledore's Army and is the Gryffindor Quidditch Chaser. Read more about Dean
Draco is a variation of Drake. Draco Malfoy is a Slytherin student the same age as Harry. He is a Prefect and a Seeker for the Slytherin Quidditch Team. He is Harry's nemesis and a suspected servant of Voldemort. Read more about Draco
Dudley Dursley is Harry's cousin who lives on Privet Drive. He is coddled by his father and mother. He is terrified of magic after a pig's tail is attached to his backside in the first book. Read more about Dudley