The Marauder's Map
A map that shows everyone at Hogwarts and their location. It alots you the ability to be able to follow or avoid those you'd like.
Harry Potter and the Prisoner of Azkaban.
J.K. Rowling
Caylee Lolley
http://www.thinkgeek.com/product/e83e/
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Sword of Gryffindor
The Swrod of Gryffindor, a goblin-made sword owned by the famous wizard Godric Gryffindor, is said to be made of from pure silver and decorated with rubies. It also has Godric Gryffindor's name engraved beneath the hilt. This sword will reveal itself to any worthy Gryffindor student in their time of need.
Harry Potter and the Chamber of Secrets (First Appearance)
J.K. Rowling
Alysia Derry-Chavez
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Novel