The Spider Eye is a poisonous food and Vanilla brewing item. It is dropped by either Spiders or Cave Spiders when killed by the player, but is not dropped by spiders that die from environmental damage (such as in a mob grinder). Spider Eyes are used to craft Fermented Spider Eyes for brewing various potions. It can be eaten, but will poison the player for four seconds, causing two hearts of damage. This damage cannot kill the player. (It cannot reduce health below 1/2 hearts).