Snape's Christmas Cracker

'Merry Christmas!' said Dumbledore, as Harry, Ron and Hermione approached the table.  'As there are so few of us, it seemed foolish to use the house tables … sit down, sit down!'

Harry, Ron and Hermione sat down side by side at the end of the table. 

'Crackers!' said Dumbledore enthusiastically, offering the end of a large silver one to Snape, who took it reluctantly and tugged.  With a bang like a gunshot, the cracker flew apart to reveal a large, pointed witch's hat topped with a stuffed vulture.

Harry, remembering the Boggart, caught Ron's eye and they both grinned.  Snape's mouth thinned and he pushed the hat towards Dumbledore, who swapped it for his wizard's hat at once.