What is Rubeus Hagrid's dog called?

Answer 1

Rubeus Hagrid's dragon is a Norwegian ridgeback by the name of Norbert.
However, Norbert was renamed Norberta by Charlie Weasley and his dragon-handling colleagues when they discovered she was female as they are more vicious than the males.

Answer 2

It was a plot device.

Professor Quirrell managed to figure out how to pass all of the challenges, except Fluffy. He knew that Hagrid always wanted a dragon and that he would say more than he was meant to if he'd had enough to drink. Quirrell got a dragon egg and, in disguise, went to the Hog's Head on the same night as Hagrid. There he bought Hagrid many drinks and talked to him about his job. At some point, Hagrid mentioned how much he wanted a Dragon and Quirrell offered to give him one if he could prove he was up to taking care of it. Hagrid said that after Fluffy, a Dragon would be easy and then told Quirrell that the trick to calming down a three-headed dog was play it some music which would send it to sleep.

This provided Quirrell with everything he needed to know to get to the Philosopher's Stone.

Answer 3

His name is Fang.

He also had a three-headed dog called Fluffy.

Answer 4

a norwegian ridgeback

Answer 5

Norbert