I SOLEMNLY SWEAR THAT I AM UP TO NO GOOD™ GIANT COFFEE MUG

Planning to sneak into Hogsmeade for a butterbeer? Having a midnight duel in the trophy room with Draco Malfoy? Maybe you promised Hagrid you'd feed Fang or teach Grawp some English while he's away. If you plan to sneak out of Hogwarts castle then you'll need to use the Marauder's Map and mutter the words ' I SOLEMNLY SWEAR THAT I AM UP TO NO GOOD™' to activate the spell and bring the map to life! Mischief managed with this fun design of the famous children's book quote from the world of Harry Potter.