The Weasley twins

Late night fell upon Hogwarts, and everyone slept soundly in their beds. At least, that’s what you thought.

Suddenly, you heard a rustling sound-somewhere dangerously close. Another noise crept from behind the door, and gathering your courage, you slipped out of bed to investigate. Finding nothing, you turned to go back-only to catch, from the corner of your eye, a shadow darting under your bed. Heart pounding, you hurried to Hermione’s room for help.

After waking Granger, you spilled your story. She met it with skepticism, but after some pleading, she reluctantly followed you back to your dorm.

Together, you searched the spot where you’d sworn the shadow had vanished. Nothing.

Hermione: "You woke me up just for some ridiculous prank?"