Weasleys' Wildfire Whiz-bangs

"Impressive, very impressive... you'll put Dr. Filibuster out of business, no problem."

- Harry Potter on Weasleys' Wildfire Whiz-bangs

Weasleys' Wildfire Whiz-bangs (also known as Wildfired Whizz-Bangs) are enchanted fireworks created by Fred and George Weasley. They are part of the Weasleys' Wizard Wheezes range of products. They are unstoppable fireworks that are charmed to explode when struck with a Stunning Spell, and to multiply by ten when hit with a Vanishing Charm. They include shocking-pink Catherine wheels, fire-breathing dragons, sparklers that spell out profanity, rockets with long tails of silver stars and firecrackers. When any two types collide, they make new kinds such as flying silver and pink pigs. It cost nine Sickles and twenty-four Knuts.

Packaging
Whiz-bangs are sold in at least two types of packages:
 * Basic Blaze Box - five Galleons each
 * Deflagration Deluxe - twenty Galleons each

History of use
Fred and George set off their entire supply in April of 1996 as part of their rebellion against the authority of Dolores Umbridge, the High Inquisitor and new Headmistress. Chaos ensued, Umbridge was outraged, many other professors neglected to assist her, and other students were ecstatic. Even Hermione Granger, despite generally disapproving of the twins' antics as a Prefect, joined in congratulating Fred and George on the act. The twins received many orders for the Whiz-bangs after the display.

Behind the scenes

 * There are evidently methods of stopping the fireworks, since they are eventually stopped. It is never made clear if only the professors of Hogwarts could do this, after obtaining the "authority" to do so from Dolores Umbridge, or if she could do it herself. It is also possible that some of the fireworks eventually burned themselves out.
 * In the film adaptation of Harry Potter and the Order of the Phoenix, Fred and George set off the fireworks in the middle of the Charms O.W.L.. Some of the fireworks went after Draco Malfoy, Vincent Crabbe, and Gregory Goyle. Fred and George then set off a dragon-shaped firework, which went after Umbridge. Just outside the Great Hall, its jaws closed around her causing it to explode and destroy all of Umbridge's Educational Decrees.

Appearances

 * Harry Potter and the Order of the Phoenix
 * Harry Potter and the Order of the Phoenix (film)
 * Harry Potter and the Half-Blood Prince (film)
 * LEGO Harry Potter: Years 5-7