Fermented Spider Eye

Fermented Spider Eye is an item that will be added in Update 0.12.0. It is a key ingredient in the brewing of negative potions.

Crafting

 * 1 Spider Eye + 1 Brown Mushroom + 1 Sugar => 1 Fermented Spider Eye

Brewing

 * 1 Fermented Spider Eye + 1 Awkward Potion = 1 Potion of Weakness
 * 1 Fermented Spider Eye + 1 Potion of Posion/Healing = 1 Potion of Harming
 * 1 Fermented Spider Eye + 1 Potion of Speed = 1 Potion of Slowness
 * 1 Fermented Spider Eye + 1 Potion of Night Vision = 1 Potion of Invisibility

Trivia

 * It is used in most negative potions.