Griphook is a fictional character from the Harry Potter Universe.
Griphook with Godric Gryffindor's Sword.
Griphook was a goblin who was working for Gringotts. He hates wizards because of how goblins have been mistreated throughout history by them.
Griphook first meets Harry Potter together with Hagrid in 1991, shortly after Harry has learned that he is a wizard. Griphook opens Harry's Gringotts vault for him, revealing Harry's huge fortune which his parents passed down to him. He also takes Harry and Hagrid to another vault, vault 713, where Hagrid quickly snaps an item Harry later learns is the Philosopher's Stone.
During the Second Wizarding War, Griphook is on the run from Voldemort and his Death Eaters with Dirk Cresswell, Ted Tonks and Dean Thomas. They are finally found by Snatchers, who kill Tonks and Cresswell, however, Dean and Griphook are taken prisoners and taken to the Malfoy Manor. Here, they are rescued by Harry, Ron and Hermione, but mainly Dobby, who died in the process.
Griphook is surprised by the respect Harry and Hermione pay towards non-human beings, and therefore agrees to help them and Ron to break into Gringotts. However, he wanted Godric Gryffindor's Sword in exchange, explaining that the sword belonged to Goblins as they made it. Harry plans to give Griphook the sword after all the Horcruxes are destroyed, but doesn't tell him.
Griphook's hate and mistrust against wizards hits him when they reach the vault where the next Horcrux is being kept. He gets hold of the sword and betrays the trio, screaming for security guards to help him deal with the intruders.
During the Battle of Hogwarts, Griphook's location is unknown, however, he loses the sword as Neville Longbottom retrieves it using the Sorting Hat. This certainly strengthened his hatred against wizards.