Gryffindor? Ravenclaw? Slytheryn? Hufflepuff? Let this mug decide! Cold, the mug shows the iconic Hogwarts Crest and the question “Which House Do You Belong Too?” When hot liquid is poured in, the mug transforms to reveal your house. Once the drink is finished the mug returns to its original state as it cools. A perfect gift for any Harry Potter fan!