What is stardew valley void spirits?

In Stardew Valley, Void Spirits are ghost-like enemies that players encounter in certain levels of the Skull Cavern, a dangerous location in the game. They are immune to most types of attacks and can only be defeated with a special sword called the Galaxy Sword. Void Spirits move quickly and can be difficult to hit, making them a challenging enemy to face. They appear to be composed of a dark, smoky substance and emit a faint blue light. When defeated, they drop a range of valuable items, including diamonds, iridium ore, and geodes.