Tom Riddle (Horcrux Diary)

Tom Marvolo Riddle is the secondary antagonist of Harry Potter And The Chamber Of Secrets. He is the horcrux and diary of Lord Voldemort who takes the form of Voldemort himself when he was 16 years old. He was given to Ginny by Lucius Malfoy and controlled her to open the Chamber of Secrets and unleash the basilisk to attack the muggleborns and steal Ginny's life energy to become physical.

Biography
Death Eater Lucius Malfoy slipped the diary preserving the Horcrux of the teenaged Tom Marvolo Riddle into a book purchased for Ginny Weasley. The Horcrux began to drain Ginny's strength and placed her under his control, using her to release the basilisk and act as Voldemort's agent. When a suspicious Ginny attempted to dispose of the diary, it was instead found and opened by Harry, who began communicating with Tom. Ginny stole the diary from Harry to prevent him from finding out about what she'd done, and Tom lured her into the Chamber of Secrets, where he attempted to take physical form. However, Harry intervened, and managed to kill the basilisk. He then used the basilisk's fang to stab the diary, unknowingly destroying one of Voldemort's Horcruxes.