An Enderman is a humanoid neutral mob that spawns occasionally in the Overworld at light levels of 7 or less, and densely populates The End. Endermen will turn hostile when provoked. They are known for their spooky presentation, their unique abilities to pick up blocks and teleport, their vulnerability to water, and the odd noises they emit.
At first, when Notch was still designing the endermen, he thought they were not 'creepy' enough, coming with the idea that having a situation which the player would want to avoid could make the enderman significantly more scary. This gave Notch the idea to implement the staring feature, where aiming the crosshair at the enderman's face would cause a suspenseful moment in which breaking eye contact would trigger an attack, as well as the enderman having the ability to teleport so that when the player has stared at the enderman, he or she would have to face a consequence for that action. They are also the only NPC's, who can pick blocks up and carry them, besides the Player, who doesn't count as a NPC.