Half blood.  Mother was a wizard, same as snape<br/><br/>Salazar Slytherin<br/>Salazar Slytherin believed that only pure-blood witches and wizards should be allowed to attend Hogwarts. He got into an argument with Godric Gryffindor about this and eventually left the school. There was a legend that Slytherin built a secret chamber somewhere in Hogwarts that only his true heir would be able to open. This chamber, called the Chamber of Secrets, contained a monster that would finish his "noble purpose" of killing all the Muggle-born students at Hogwarts. As Slytherin's heir, Tom Riddle did open the Chamber and released the monster, a basilisk. Harry Potter defeated the basilisk with the help of Fawkes the phoenix and the sword of Gryffindor (CS).<br/><br/>That's why I'm so confused, but it is your decision just was a bit surprised.