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.
While it's true that Voldemort is a descendant of Salazar Slytherin, he is the “Heir of Slytherin” because he is a parselmouth and he figures out he needs to communicate with the basilisk to open the Chamber of Secrets. Tom Riddle, Jr simply appropriates the title “Heir of Slytherin” for himself.
The story of Chamber of Secrets, as you know, is that the Heir of Slytherin has returned and he's out for Mudbloods. The Heir of Slytherin turns out to be Ginny Weasley, who is being controlled via a magical diary that once belonged to Tom Riddle, AKA Voldemort.
Originally Answered: How did Tom know he was the heir of Slytherin? Tom Riddle/Voldemort believed himself to be special before he ever found out about Hogwarts. He became obsessed with learning about his parentage, but he only had two real clues to his heritage. The name “Marvolo” was his maternal grandfather's name.
The Heir of Ravenclaw was an individual prophesized by the centaur Harmonthrep (Ajrand) to bring honor and glory to the House of Ravenclaw. The Heir of Ravenclaw was in time revealed to be Brian Dumbledore (Ajrand).
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.
Harry is the magical Heir of Gryffindor (and he's also a descendent of Godric), Neville of Hufflepuff, Hermione of Slytherin and Luna of Ravenclaw.
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 Head of Slytherin is Horace Slughorn (who left the role to Severus Snape for fifteen years before taking it up again in 1996) and the House's patron ghost is the Bloody Baron.
Only one heir is currently confirmed and known; Tom Marvolo Riddle/Lord Voldemort, heir of Salazar Slytherin. Well for now, nobody knows the Heir of Gryffindor, Ravenclaw and Hufflepuff.
Riddle ultimately changed his name, by way of an anagram, from "Tom Marvolo Riddle" to "I am Lord Voldemort", as a way of removing his own heritage and of exalting himself, and he killed the Riddle family, partly because they were Muggles, and partly because they abandoned him and his mother.
Type of Villain
Salazar Slytherin is the posthumous overarching antagonist of the Harry Potter franchise. He is one of the four founders of Hogwarts who founded the House of Slytherin and the ancestor of Lord Voldemort.
He borrowed the Invisibility Cloak from James Potter once. He defeated the owner of the Elder Wand, Gellert Grindelwald, in a duel, and thus became the owner of that super-vital artifact. And, Dumbledore also sought out the Resurrection Stone after the death of his sister, Ariana.
Following his failure to obtain an important prophecy at the end of Order of the Phoenix, Lucius is sent to Azkaban for a while until Voldemort breaks him out, although he doesn't play much of a role in the series going forward.
Hermione Malfoy (née Granger) is the daughter of Richard Granger and Jean Granger, Wife of Draco Malfoy, daughter-in-law of Lucius Malfoy and Narcissa Malfoy and Sister-in-law of Draco Malfoy's sister Miss Malfoy.
Peter Pettigrew, (a.k.a. Wormtail), is the only Death Eater known to have been in a House other than Slytherin (Gryffindor) while at Hogwarts.
Alfred Lewis Enoch (born 2 December 1988) is a British and Brazilian actor. He is best known for playing Dean Thomas in the Harry Potter film series and Wes Gibbins in the ABC legal thriller television series How to Get Away with Murder.
Harry James Potter holds half-blood status in Rowling's imagined wizarding world because his mother is Muggle-born and his father is pure-blood. There are three main blood statuses; pure-blood, half-blood, and Muggle-born, which are all methods of determining a witch or wizard's magical lineage.
Godric Gryffindor married Sarena Gryffindor (born Deana). They had one daughter: Sarena Peverall (born Gryffindor).
Credence Isn't Voldemort's Dad But He Could Be Snape's Grandpa. Before Fantastic Beasts and Where to Find Them came out, it seemed like the story's only real Potter connection would be Newt Scamander's relation to Luna Lovegood and a Dumbledore name-drop.
Moaning Myrtle
Born in the late 1920s to Muggle parents, Myrtle Warren started her Hogwarts life in the early 1940s, where she was sorted into Ravenclaw. She had no friends, and was bullied relentlessly because of her glasses and acne.
At Hogwarts, she, along with her sisters, was sorted into Slytherin. It is suggested in the novels that, as a student, Bellatrix associated with a group of students – including Rodolphus Lestrange, Severus Snape, Avery, Evan Rosier and Wilkes – who nearly all became Death Eaters.