Griphook is the goblin who helps Harry break into Gringotts in the Harry Potter book series.
Griphook works at Gringotts Wizarding Bank and first appears when Harry visits the bank with Hagrid in Harry Potter and the Philosopher’s Stone. In Harry Potter and the Deathly Hallows, Harry, Ron, and Hermione need his expertise to enter Bellatrix Lestrange’s high-security vault, where Helga Hufflepuff’s Cup is hidden.
Griphook agrees to help in exchange for the Sword of Gryffindor. He guides the group through the bank during the break-in, but later takes the sword for himself after the escape. The character’s knowledge reflects the specialized security of Gringotts, including dragon guards, multiplying treasure, and the Thief’s Downfall. Bogrod is another goblin involved in the break-in, but he is not the goblin who plans and leads it.