Kids Marauder's Map T-Shirt
Do you solemnly swear that you're up to no good? Then Join Moony, Wormtail, Padfoot, and Prongs as they maneuver their way around Hogwarts leaving Filch none-the-wiser. The Whomping Willow and paths leading to the castle feature character names, while the shining copper foil enhances the majesty of Hogwarts as well as echoing the traditional colours of the Marauder's Map.
Just don't forget to declare "mischief managed" as you pull yourself away from your shortcut to Honeydukes.