Go for a walk and find a test subject

Harry stepped outside of the Room. “I won’t get in trouble for wandering the halls, no matter the time.” he mumbled to himself, giving him all the free time in the world. Still, Harry thought to himself, it would be best not to have to change a teacher just yet. “I have the Marauder’s Map in my pocket.” The crinkle of parchment next to his hand surprised him enough to jump, but it made him smile none the less.

Harry wandered the halls aimlessly for a while, changing various statues and gargoyles and then changing them right back to test the limits of what he could do. Soon though he grew bored with the inanimate objects and pulled the map out, placing the wand to the paper... and stopping himself.

“Uh oh. The map’s password could change me horribly.” Harry said to himself, mentally reciting the passcode (I solemnly swear I am up to no good) and trying to guess what could happen if he said it. Red eyes and a missing nose came to his mind. “Um, let’s see, the map knows I am the son of James ‘Prongs’ Potter and doesn’t need me to give a passcode?” The map swirled and wrote out ‘Hi Son’ before forming the map proper.

Harry’s eyes traced over the map for a good test subject, locking on to a single one in the Prefect bath. “Well, well, well... This could be fun.” He smiled evily to himself.