Empty Bucket

Buckets are useful tools that allow the transportation of water and lava. This theoretically makes it both a tool and a weapon (throw lava on an enemy). It is also a great way to make obsidian (f.e. transporting lava to the surface or water to the underworld).

Three Iron Bars are needed to craft one, using an anvil. Each bucket can transport one block of either water or lava.

For an unknown reason, it is possible to put an empty bucket on top of your head in the helmet slot, it does not seem to provide the player with any benefit however.

If you fill a bucket of water and dump the water inside other water blocks the water will dissapear making it a fast way to remove unwanted water.