Sorting statues

These were four magical statues made of wood that stood inside the entrance hall of Ilvermorny Castle. They depicted the house mascots: a Horned Serpent, a Thunderbird, a Wampus cat and a Pukwudgie with an arrow. They were used to sort the students into the four houses. When a student was accepted into Horned Serpent, the serpent horn began to glow. When a student was Sorted into Wampus, the Wampus cat roared, when a student was sorted Thunderbird, it flapped its wings, and when a student was accepted into Pukwudgie, it rose its arrow. It happened at times that a student was accepted into several houses, in which case they could choose which house they wanted to belong to.

Appearances
Pottermore (mentioned only)