Enderman

The Enderman is a rare mob that will be introduced in version 1.8; The Adventure Update. The Endermen are depicted as 3 meter tall, black creatures with long arms and legs. They also have the ability to pick up and move blocks around. They are generally peaceful. If you look at them, by placing your crosshair directly over them, they freeze, stare back at you, open their mouth and become hostile. They stay frozen as long as you keep looking at them. When you look away, they will quickly run towards you; if they are a long distance away, they will teleport several times until close enough to reach you. They will only teleport to somewhere you can see. Endermen can teleport about once per second. Endermen take damage from coming in contact with water (including water blocks and rain) and sunlight. Their exact size is 0.6x0.6x2.9.

Preventing Attacks
Wearing a pumpkin on your head, along with pressing F1 to hide the HUD, will prevent an Enderman to charge you. Having an Ender pearl in your inventory will reduce their maximum range to the half, giving you the ability to get a closer look. It is important to note that the Endermen will return aggresion if you attack them regardless. It is safe to look at them through transparent blocks like glass, glass panes, iron bars and ice.

Killing Endermen
Despite their appearance, Endermen are easier to kill than most other mobs, since they are damaged by water, sunlight, fire, lava and attacks alike. Emptying a bucket of water on the ground may be useful in confined spaces, as you can damage the Enderman with the water and your attacks at the same time. Arrows and all types of sword are effective against one, though wood and stone swords may not deal enough damage to kill the Enderman before it kills you.

Trivia

 * The name "Enderman" is a subtle reference to the popular internet phenomenon Slender Man. The name was given to the mob by Notch in a Reddit thread.
 * Due to the Slender Man similarities, many have petitioned to change the name "Endermen" to "Far Landers". Notch has stated however that he will not change their name, regardless of this petition, going as far as to joke that he should change the name of the Far Lands to "The End" instead.
 * At the PAX Beta 1.8 demo, Endermen dropped diamonds.
 * Endermen occasionally emit black smoke-like particles..
 * They may also produce a strange, croaky squark, however that may just be the background noise of the video.
 * Endermen have the ability to open their mouths. In their texture, their jaw is separated from their skull and in the 1.8 Official Trailer, an Enderman attacked the camera with its mouth open. This makes the Enderman the first mob with the ability to physically open their mouths without switching to a different texture. They only open their mouths when they attack. Due to the player's perspective, the player sees the back of the Enderman's head when they open their mouths. If a player is one block higher, they see through the Enderman's open mouth. They open their mouths by moving their skulls higher than their jaw. (Similar to the Canadians from South Park.)
 * In the 1.8 prerelease, Endermen sound like zombies, which is almost certainly a placeholder until the release when the real sound will download into the resources folder.
 * Endermen's eyes glow in the dark, like spiders'.
 * Endermen's full body glows in the fog. (Like Spiders)
 * Endermen seem to shake while you look at them.
 * When you pause the game, the Enderman will keep shaking.