Enjoy a cup of tea as your guardian looks over you with this wonderful Harry Potter Patronus Heat Change Mug. This Heat Change Mug features the phrase "Expecto Patronum" on its side, in electric blue writing on a dark black background when cold. And once you've poured in your favorite hot beverage and it warms up, Harry's own stag Patronus appears from the darkness. This mug makes a fabulous gift for Harry Potter fans and is a great accompaniment to your next mid-Potter tea-break. Hand wash only. Not dishwasher safe. Do not microwave.