As Harry Potter roamed the hallways of the castle, he saw a light down the end of the hallway, he chooses to follow it; only to see a dementor. But a witch already stands before it, a wand in front of them, producing a Patronus charm in the form of a Pegasus, Harry had been studying Patronus forms... As a Patronus, they represent power, determination, and a free spirit. This witch was a powerful one, with their green and silver tie.