What did Hagrid hatch from an egg?

Hagrid hatched a Norwegian Ridgeback dragon named Norberta (previously Norbert, however Charlie Weasley tells him that Norbert is female) Norberta, previously named Norbert, is a Norwegian Ridgeback dragon that Hagrid had acquired as an egg from a mysterious, hooded stranger, who turned out to be Professor Quirrell. Hagrid helps the dragon hatch from the egg. Norbert becomes very dangerous and much bigger in the weeks following, so Harry, Ron, and Hermione finally persuade Hagrid to give her to Ron's older brother Charlie, who is studying dragons in Romania. Harry and Hermione take Norbert up in a crate under Harry's Cloak of Invisibility. In the Deathly Hallows, Charlie Weasley revealed to Hagrid that Norbert was actually female, and had been renamed Norberta. Charlie notes that female dragons are more vicious than the males.