Enderman

 Endermen , are neutral mobs, meaning that they will not attack unless provoked. If you make eye contact with one, they will freeze and open their mouth. It will stay frozen until you look away from it, and after that it will teleport and be aggressive to you. They can pick up blocks that take a short time to break by hand like dirt and sand. They can not pick up blocks such as stone and wood.Enderman are primarily nocturnal creatures as they are often found at night,however since the dimension known as the end is eternally night there are enderman everywhere.It is rare to see an enderman in sunlight and if one is out it will often teleport away into a shaded area when someone comes near.They also have a weakness to water as it causes damage to them when they come in contact with one,that is why despite it being dark during a storm an enderman will not be seen.

A good strategy to defeat endermen is to have your back against a wall and a roof over your head, so that way the only way an Enderman can attack you is from the front.

Another good strategy to defeat Endermen is to make a 4 block high pillar made of any block (not sand or gravel), while you're underneath. The Endermen cannot attack you since you are too high.They bear a resemblance to the slenderman as they are incredibly lanky and have arms that reach down their ankles,the only difference in appearence is the enderman has eyes while the slenderman is faceless and the enderman is all black while the slenderman is wearing what looks like a suit and has a white head.