Gunpowder

Gunpowder, formerly known as sulphur, is an item that can be obtained by killing Creepers, Ghasts, witches, or looting dungeon chests. It is used to craft TNT, fire charges, firework stars, and firework rockets and can be brewed with any potion to make a splash potion.

From Creepers
Creepers have a chance of dropping up to 2 pieces of gunpowder upon death.

From Ghasts
Ghasts have a chance of dropping up to 2 pieces of gunpowder upon death.

From witches
Witches have a chance of dropping up to 6 pieces of gunpowder upon death.

From dungeon chests
Dungeon chests have a 1 in 12 chance of containing gunpowder.

History
Schießpulver Sulphur/es Poudre à canon Puskapor 화약 Buskruit Proch pt-br:Gunpowder Порох 火药