J.K. Rowling identified Professor McGonagall and Peter Pettigrew as known Hatstalls, while also considering Neville, Harry, and Hermione to have given the Sorting Hat pause. Harry and Neville both ...

As the hat is placed on each student's head, it investigates their minds, decides which house the student is best suited to, and calls the house out to the crowd. In effect, the Sorting Hat is ...