Enderman are naturally fearful creatures, and they are scared of a number of things. The most prominent fear that Enderman have is water. Enderman will run away from any source of water, including rain, pools of water, or even just water in a bucket.
They are also scared of picking up any items, even items dropped by a player. Additionally, Enderman are afraid of the color purple, and so they will avoid any sort of light source or block which is a shade of purple.
Additionally, Enderman will avoid the use of any end portals and be repelled by the sound of the ender dragon. Lastly, Enderman can be scared away by the sound of a human or player, as they will flee upon hearing the sound of someone nearby.
