Nagini is Voldemort's huge familiar snake, introduced in "Harry Potter and the Goblet of Fire". According to Indian mythology, the name Nagini means a female serpent that occasionally takes human form. Voldemort made Nagini his final Horcrux (an object used to store part of a person's soul, protecting that person from death) by murdering a muggle tramp when he was hiding in the forests of Albania. Due to this connection, Voldemort has complete control over the snake.

"Harry Potter and the Goblet of Fire" is a fantasy novel written by British author J. K. Rowling and the fourth novel in the "Harry Potter" series. It follows Harry Potter, a wizard in his fourth year at Hogwarts School of Witchcraft and Wizardry, and the mystery surrounding the entry of Harry's name into the Triwizard Tournament, in which he is forced to compete.

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