Dr. Filibuster's Fabulous Wet-Start, No-Heat Fireworks

From Harry Potter Wiki

Dr. Filibuster's Fabulous Wet-Start, No-Heat Fireworks are magical fireworks that are presumably set off with water.

[edit] Known Uses

Fred and George Weasley and Lee Jordan bought some at Gambol and Japes Wizarding Joke Shop in 1992. Harry Potter later borrowed a firework from Fred and used it to explode Gregory Goyle's cauldron in Potions class. This created a distraction that allowed Hermione Granger to slip out of the room to get the boomslang skin that she required.

On the way to Hogwarts in 1994, Fred's trunk fell open, setting off a number of the Filibuster fireworks he'd packed. The Muggle taxi driver who was carrying the trunk was alarmed by the incident.