The dragon Hagrid secretly raises in Harry Potter and the Philosopher’s Stone is named Norbert.
Hagrid wins the dragon egg from a stranger in a pub after discussing how to get past Fluffy, the three-headed dog guarding the trapdoor at Hogwarts. The egg hatches in Hagrid’s hut, and he names the dragon Norbert. Harry, Ron, and Hermione soon discover that caring for a rapidly growing dragon is impossible and dangerous.
Norbert bites Ron and grows too large to remain hidden. Hagrid eventually arranges for the dragon to be taken to Romania, where Charlie Weasley works with dragons. Charlie later identifies Norbert as female and renames her Norberta.
The name Norbert is therefore the name used during the Hogwarts episode, while Norberta is the later corrected name. Norbert is not Hagrid’s dog Fang or the giant spider Aragog, both of which are also associated with Hagrid.