In the Chamber itself, we see a large statue of a wizard, which Harry presumes is Salazar Slytherin. We also meet Tom Riddle, who is, as it turns out, the heir of Slytherin. Present only in spirit, he has all the same been controlling Ginny, and having her act as Slytherin's heir.
Neither of them is Slytherin's heir. Although, as Dumbledore says, Harry's ability to speak Parseltongue is a skill accidentally transferred by Slytherin's actual heir, Voldemort, when he tried to kill Harry as a baby. So perhaps this is one myth with a bit of truth to it.
Harry is the Heir of Gryffindor (though his powers have been bound by his father when he was a baby), Neville is the Heir of Hufflepuff, Meghan (OFC, daughter of Sirius) is the Heir of Ravenclaw. Harry/Ginny, Ron/Hermione, Remus/Tonks. Sixth year. After a rare magical illness Harry becomes outstandingly powerful.
Her real parents were Daneel and Dean Novak, Pureblooded wizards. Turns out Daneel was Tom Riddles younger sister, Daneel Riddle. Of course, the Riddles were related to Salzar Slytherin himself, and this made Hermione the living heir of Slytherin. The problem with being a female Slytherin heir, is that they're cursed.
In the warehouse, Grisha explains that she was a student with Riddle at Hogwarts, who along with Wiglaf Sigurdsson and Lazarus Smith were the true heirs of the Hogwarts founders (Gryffindor, Slytherin, Ravenclaw, and Hufflepuff, respectively). The heirs formed a club dedicated to "making the world a better place".
The Heir of Hufflepuff was none other than Cedric Diggory, who was well on his way to fulfilling the prophecy of the Heir of Hufflepuff when he was tragically murdered by Peter Pettigrew. Thus, the prophecy would remain unfulfilled forever.
Who were the heirs of each of the four founders of Hogwarts? Ravenclaw heir is the Grey Lady; aka Helena Ravenclaw. We do not know if she has any other children or if Helena had any children. So we don't know if there are any Ravenclaw heirs alive at the time of Harry's hogwarts days.
Albus was named in memory of Albus Dumbledore and Severus Snape, two former headmasters of Hogwarts School of Witchcraft and Wizardry and both great wizards that his father knew. In 2017, Albus began his education at Hogwarts with Rose Granger-Weasley and Scorpius Malfoy and was sorted into Slytherin House.
After Voldemort's death in 1998, Delphi became Salazar Slytherin's last known heir.
The Prince of Slytherin is a title bestowed upon members of Slytherin House who are able to impress the Hydra Throne and gain control over Slytherin House through subtle methods.
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).
Albus Dumbledore:
He wears half-moon spectacles and a long purple cloak. He has a scar on his left knee which is a perfect map of the London Underground. As a schoolboy, he was in Gryffindor house.
Godric Gryffindor, the founder of Gryffindor house, was one of the most powerful wizards of his age, so powerful that he was said to be the greatest duelist of that era. Always ready for battle, Godric wouldn't just use a simple wand, he'd also wield a mighty sword.
Harry Potter came very close to being sorted into Slytherin before he persuaded the Hat to sort him into Gryffindor. Yet the spectre of Slytherin haunted him for some time afterwards, becoming particularly potent in Harry Potter and the Chamber of Secrets, when he was rumoured to be the heir of Slytherin.
Moaning Myrtle is a ghost of a female student that can be found crying in girls' lavatories. She belongs to Ravenclaw and was killed by Basilisk for being a Muggle-born witch.
In her first year at Hogwarts, Rose had undergone the trial of the Sorting Hat as all the students in her first year. She was one of the first students to be called and, surpassing the expectations of teachers - especially Flitwick, she was selected for Gryffindor.
At Hogwarts, she, along with her sisters, was sorted into Slytherin.
The biggest revelation in Harry Potter and the Cursed Child was that Lord Voldemort had a daughter with Bellatrix Lestrange, who was named Delphini.
He did not love anyone, and did not care to be loved. He felt nothing for his family, and only wanted his friends in school to rally around him because he wanted to hold power over them. Bellatrix Lestrange was obviously in love with him and worshiped him, but he only cared for her servitude, not her.
Scorpius Malfoy
He joins Hogwarts at the same time as Albus Potter, forming an unlike friendship on the Hogwarts Express. This grows when the two of them are sorted into the same house, Slytherin. Unlike Draco, Scorpius focuses his Slytherin-like determination into his studies, being an avid reader.
In 2019, Lily began her education at Hogwarts School of Witchcraft and Wizardry and was sorted into Gryffindor House.
Much of the plot hinges on Harry's tumultuous relationship with his son, Albus — a relationship that culminates in Harry saying, “Sometimes I wish you weren't my son!” And I knew, in my heart of hearts, that Harry would never say that. He just wouldn't.
Harry himself is a half-blood, since his pure-blood father, James, married a Muggle-born witch named Lily, and his maternal grandparents were Muggles.
Harry Potter, a living descendant of the third brother was later given the cloak by Albus Dumbledore. Long ago, it is said, Death created the Deathly Hallows. The Elder Wand; The Resurrection Stone; and The Cloak of Invisibility, together, make the beholder a master of death.
Through his mother's family, he is the last descendant of the wizard Salazar Slytherin, one of the four founders of Hogwarts School of Witchcraft and Wizardry.