Slimeball

The Slimeball is an item dropped by Slimes. There are currently no uses for it. Notch confirmed that they are going to be craftable in a later beta update.

0-2 slime balls will be dropped when a small slime is killed. Only small slimes will drop Slimeballs on death, and larger slimes will duplicate into smaller slimes (Beta 1.3_01 update changed it so that if you use an item that deals more than half a heart to kill a slime, the slime will not a drop slimeball(s) and the slime will not split into smaller slimes.). As slimeballs come from Slimes, they are a renewable resource.

Some users use these as tokens or cash in multiplayer servers, since it has no use and is more realistic, since server mods do not use up inventory space. When in Single Player, some players use them to show how many slimes they have killed. In some custom maps and challenges, they are used as score, or as triggers for pressure plates as the player is guaranteed to have no other use for them.

There are plans and ideas that slimeballs could act as eggs, along with other uses. They could be thrown like eggs or snowballs and may spawn Slimes certain times. Some players use mods that allow this to happen. But it is rare.