Enderman

Endermen are 3-block tall mobs that can pick up blocks. They naturally spawn all over the End and rarely in the Overworld. Endermen are provoked by looking at their body from 64 or less blocks away. When your cross-hair is on the Enderman, he will open his jaw and wobble until you take your cross-hair away. When you do, he will teleport toward you and start to kill you. They are the only source of ender pearls,and you can get Eye of Ender via trading or crafting ender pearl with blaze powder. You need Eye of Ender to go to the End.

Appearence
Endermen are 3 blocks tall, have long limbs and purple eyes. They emit purple smoke when they are ready to teleport. Endermen are black.

Behavior
Endermen have the ability to teleport, and will teleport randomly in daytime. Endermen dont like water and will try to teleport out of it. They are often seen holding blocks, and below you can see what blocks they can hold.

Movable blocks
Endermen can only pick up certain blocks, you they dont destroy your house. They cannot pick up primed TNT. Also, if you see an Enderman carrying TNT, it can be funny to place redstone torches everywhere so when the Enderman places the block he'll blow up. They can carry:

Block, Mycelium, Sand, Gravel, Clay, Flowers, Mushrooms, Cacti, Pumpkins, Melons, TNT

Note: Endermen wont purposely blow up your stuff, or destroy your bases.

Defence
If you accidentally provoke an Enderman, here are some tips to help fighting one:

- Place a bucket of water at your feet. This means you wont get caught in the current, and the Enderman will go away, since Endermen dont like water, and most times take damage from it.

- Go into daylight, and then look at the Enderman again. This will make the Enderman neutral.