Harry Potter Keyring (History of Magic)
 
Hogwarts class History of Magic is the only lessons to be taught by a ghost and is (apparently) the most boring subject while Professor Cuthbert Binns drones on. It is believed that he sat down in front of the staff room fireplace, fell asleep and died; the next day, his spirit simply got up and went to class to teach, leaving his body behind.
 
This metal keyring proudly boasts the same symbol from the book, History of Magic by the most famous historian from the Wizarding World, Bathilda Bagshot.
 
Officially Licensed Harry Potter Merchandise