How To Find And Use Minecraft Slimeballs, Defeat Slimes, And Farm Slime Blocks Minecraft Slimes are a hostile mob, but they drop helpful Slimeballs that can be used for a variety of things.

To get Heavy Core in Minecraft, you have to open Vaults using Trial Keys. These Vaults are special blocks that may look like spawners. They are only generated in structures called Trial Chambers.