The Enderman is a mob that will be introduced when 1.8 comes out. The Enderman are described as tall & lanky subjects. They are about 3 meters tall with long arms. The Enderman have the ability to pick up blocks and move them around. However they are usually peaceful and only become hostile when you place your cursor directly over them.
The Enderman stay frozen as long as you keep looking at them but the second you turn away they will come after you. If you get too far away from them they will teleport to you. The Enderman can teleport multiple times and is said to be able to teleport once per second.