Ender Spiders are mobs that live in the End and rarely in the Overworld. Their eyes glow pinkish violet rather than red. They are 1.5x bigger than a normal spider and are a favoured pet for Endi homes.
Ender Spiders will often be hiding in an End Crystal. When the crystal blows up, they jump out and off at the closest entity. What is amusing is that they will attack other Ender Spiders, Endermen, Ender Dragons, Ender Ghasts, or anything else that is in the vicinity of 20 blocks. They can be fed Eyes of Ender so they ignore the Player for about 2-7 minutes before trying to attack everything again. They drop Enderpearls upon death and, very rarely, Ender Ribbons. Purple particles similar to an Enderman always circle them, though they can't teleport.
Ender Spiders live in the End and have a 5% chance to spawn with a single Enderman or a group of Endermen in the Overworld.