The importance of this ability as Hermione explained to Harry, "It matters because being able to talk to snakes was what Salazar Slytherin was famous for. That's why the symbol of Slytherin House is a serpent."

Lord Voldemort is also a Parselmouth and this is evident in the way he controls Nagini, a snake that does whatever of the Dark Wizard commands it.

In the fifth book of the series, one of Hogwarts' professors, Professor Trelawney, provided an insight on the link between Harry and Voldemort when she went into a trance and uttered in the presence of Harry:

"The one with the power to vanquish the- Dark Lord approaches… born to those who have thrice defied him, born as the seventh month dies & #8230; and the Dark Lord will mark him as his equal, but he will have power the Dark Lord knows not & #8230;and either must...
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