Rubeus Hagrid
Despite Harry's aunt and uncle's desperate prevention of Harry learning about his abilities, their efforts are in vain. Harry meets a half-giant, Rubeus Hagrid, who is also his first contact with the wizarding world. Hagrid reveals himself to be the Keeper of Keys and Grounds at Hogwarts as well as some of Harry's history. Harry learns that, as a baby, he witnessed his parents' murder by the power-obsessed dark wizard Lord Voldemort (more commonly known by the magical community as You-Know-Who or He-Who-Must-Not-Be-Named, and by Albus Dumbledore as Tom Marvolo Riddle) who subsequently attempted to kill him as well. Instead, the unexpected happened: Harry survived with only a lightning-shaped scar on his forehead as a memento of the attack, and Voldemort disappeared soon afterwards, gravely weakened by his own rebounding curse.