Christmas cracker

A Christmas cracker is a party favour given out at Christmas in the United Kingdom, as well as in other Commonwealth countries like Australia, Canada, and New Zealand. Crackers consist of a cardboard tube wrapped in festive paper that is twisted at either end like a sweet wrapper. Inside of the tube are prizes, and, in order to get them out, two people each hold one end of the cracker and pull it apart. The split is accompanied by a bang (from which the name cracker is derived).

Muggle vs. wizard crackers
Muggle crackers contain several items — typically a paper hat, a plastic toy, and a slip of paper with a joke printed on it — and produce a small bang because a thin strip of chemically-infused cardboard is torn in half when the cracker is pulled apart.

Wizard crackers, in contrast, go off with a bang as loud as a cannon blast, enveloping everyone nearby in a cloud of blue smoke. They contain the same hat, gift, and joke as the Muggle variety, but the hats are real and the gifts are extremely unique, even peculiar.

One brand of wizard crackers was Cribbages Wizarding Crackers.

Wizard crackers at Hogwarts
Wizard crackers were given out at the Christmas feast every year at Hogwarts. A stack of them was placed every few feet along each of the tables in the Great Hall.

Hats

 * A rear-admiral's hat, received by Harry Potter in 1991.
 * A flowered bonnet, received by Albus Dumbledore in 1991.
 * A top hat, received by Minerva McGonagall in 1991.
 * A witch's hat topped with a stuffed vulture, received by either Albus Dumbledore or Severus Snape in 1993, apparently in response to an incident earlier that year involving Neville Longbottom's Boggart.

Gifts

 * Several live white mice, received by Harry Potter in 1991, all of which disappeared. Harry assumed that they were later eaten by Mrs. Norris.
 * A pack of non-explodable, luminous balloons, received by Harry Potter in 1991.
 * A grow-your-own-warts kit, received by Harry Potter in 1991.
 * A wizard chess set, received by Harry Potter in 1991.

Appearances

 * Harry Potter and the Philosopher's Stone
 * Harry Potter and the Prisoner of Azkaban
 * Harry Potter and the Goblet of Fire