First Book
Rubeus Hagrid went for a drink in the Hog's Head where he met Professor Quirinus Quirrell who was in disguise. Quirrell was attempting to find out how to get past the protection Hagrid had given the Philosopher's Stone in the castle at Hogwarts, which was a three-headed dog by the name of Fluffy. After a game of cards Quirrell offered Hagrid a dragon egg as a prize, something Hagrid had always wanted but was illegal. During the conversation about magical creatures Quirrell managed to get Hagrid to reveal that playing music to Fluffy would send him to sleep.