Harry Potter: Patronus Heat Change Mug

This Harry Potter heat changing mug is sure to cast a magic spell over your morning brew. Cold, the mug shows the famous 'Expecto Patronum' charm which wizards and wizards can cast when they need special protection from Dementors. When hot liquid is poured in, the mug transforms to reveal Harry's stag Patronus on the front and a Dementor watching from the sky on the back.