Known Parselmouths Ginny Weasley was able to speak Parseltongue while she was possessed by Tom Riddle's Diary, which enabled her to open the Chamber of Secrets.
To date, the ability to speak Parseltongue has been almost entirely associated with those who can show direct descent from Salazar Slytherin. Harry, it turns out, can speak Parseltongue, though he was apparently not born with that ability.
The Tom Riddle incident
Lord Voldemort lived inside those pages, and Ginny was eventually possessed as the Dark wizard began to absorb her strength, control her into opening the Chamber of Secrets, and nearly killed her. The event, though undeniably traumatic, was a pivotal point in Ginny's life.
Ron spoke Parseltongue in Harry Potter and the Deathly Hallows to open the Chamber of Secrets.
Ginny was possessed by the spirit/portion of soul that was inside Tom Riddle's diary/horcrux. This is what enabled her to open the Chamber of Secrets. Tom Riddle was the only known remaining descendant of Salazar Slytherin and a Parselmouth (Parseltongue is the language).
SHE'S A PROFICIENT AND POWERFUL WITCH
J.K. Rowling has stated one of the reasons Ginny is gifted is due to the fact she was a seventh child and the first female Weasley born in generations, which ties into the superstition of the seventh daughter of a seventh daughter.
As J.K Rowling revealed, Albus Dumbledore had mastered Parseltongue too – although he could not speak it aloud. We're not sure why Albus learnt the language, but perhaps the Hogwarts headmaster wanted a better understanding of Voldemort.
Draco's refusal to reveal Harry's identity to Bellatrix was not because he liked him. It was because he believed that Harry was the only chance they had at defeating Voldemort. At first, Draco admired and revered Voldemort until he threatened his family's safety.
However, while Goyle is quickly subdued, Crabbe starts using the killing curse Avada Kedavra, showing his complete lack of compunction and humanity by this time. In the end, Crabbe is consumed by his own malice, being devoured by the Fiendfyre he has summoned.
Harry and Draco were both parselmouths: one born, the other taught. They fought in parseltongue in front of the entire school on a near-daily basis, and the hisses and snarls were easily heard as threats.
Once he was strong enough he began pouring bits of his soul into her in an effort to poison her soul so that he could weaken her, and eventually become strong enough to be freed from the diary and gain a life of his own, having sapped the life out of Ginny by poisoning her soul.
Myrtle's life was cut shockingly short when she was killed by the Basilisk at Tom Riddle's command.
Gabriel Cordova is a character in Netflix's Ginny & Georgia. He is portrayed by Alex Mallari Jr..
After Lord Voldemort destroyed the fragment of his soul residing in Harry, Harry seemingly lost the ability to speak Parseltongue, about which he was glad and relieved. Over the next twenty-two years, he never attempted to speak the language, presuming that it had died with Voldemort.
He also divided his soul into seven Horcruxes to make himself immortal. Albus Percival Wulfric Brian Dumbledore was the only wizard Voldemort ever feared and the only one who could have defeated him in a duel. Albus Dumbledore is the most powerful wizard in the Harry Potter.
Harry and Neville are both heirs of Gryffindor, as are all the other wizards who did the same throughout time.
Though Harry encountered many opportunities that deemed Avada Kedavra necessary, it remains as one of the Unforgivable Curses Harry Potter never cast. For one, he viewed the spell as an immoral practice commonly used by users of the Dark Arts.
What she hadn't bargained for was the hex Hermione Granger had cast on the very sign-up sheet itself, designed so that anybody who betrayed the trust of the Army would immediately break out in painful, ugly spots on their face, aptly spelling out the word 'SNEAK'.
Draco Malfoy's mother Narcissa was cold, cunning and devoted to the Dark Lord. But she was also a mother, which meant she was willing to risk everything to make sure her son was safe. When Harry survived Voldemort's Killing Curse for the second time, Narcissa pretended he was dead so she could get to Draco.
Narcissa's greatest moment, however, was when she chose to betray Voldemort in Harry Potter and the Deathly Hallows. Not knowing whether Draco was alive or dead, Narcissa chose to lie to the Dark Lord rather than risk losing her son.
She was remorseless and was cackling in glee after she had murdered Sirius. Bellatrix couldn't stop raving about it and showed it by singing “I killed Sirius Black” multiple times.
When Voldemort attempts to kill Harry his ability to speak Parseltongue is passed to Harry through the small bit of the former's soul. After that bit of soul is destroyed, Harry loses this ability.
Lily Evans is a Parselmouth and Sorted into Slytherin.
The only known direct descendants from Salazar Slytherin were the Gaunts, who for the most part shared their ancestor's beliefs in the purity of wizard blood. They also spoke in Parseltongue between themselves. Tom Marvolo Riddle was the last descendant of the Gaunt family and spoke Parseltongue as well.