Dragon Egg

A dragon egg is a block that spawns on top of the bedrock portal created by the defeat of the Ender Dragon in The End. They currently have no explicit purpose, but are tricky to collect. One of the ways to collect them is to punch a block, then move the cursor over the egg to break it.

They currently serve no purpose, other than as a trophy or decoration.

Behavior
Clicking on the egg in survival causes it to teleport to a place nearby (up to seven blocks vertically and fifteen blocks horizontally), creating the same particles as Endermen, Nether Portals, and Ender Chests. It may teleport into the air and subsequently fall to ground.

Like Sand and Gravel, Dragon Eggs fall when unsupported, and if they land on a non-solid block, (such as a Torch, Slab or Tall Grass) they will drop as a resource. They cannot suffocate the player by falling onto them.

To obtain the dragon egg, the player may push it with a piston, detonate it with TNT, or place any non-solid block under the block the egg rests on and then destroy that block so the egg falls onto it. You can also click the left mouse button while looking away from the egg and then move the cursor towards it (still holding the button), this will allow you to mine it up and it's probably one of the easiest ways to obtain the egg. It is possible for the player to hit one while it is still moving to the point it breaks, however this is difficult.

You can get a dragon egg in creative by clicking on it with the pick block key. This will add it to your inventory without breaking it. Keep in mind this is only for creative mode.

History
The Dragon Egg is an item first mentioned by Notch on the 27th of October, 2011 on which Notch was supposedly working before the feature freeze, though it seems to have been worked on during it.

The Dragon Egg was first introduced in Beta 1.9 Pre-release 6 (November 11th 2011).

Bugs

 * Dragon Eggs in SMP are extremely buggy. They may lag the server until the server is required to shut down.

Trivia

 * Destroying the egg accompanying Overworld Portal with water or lava will also cause it to drop as a resource.
 * Ender Dragons destroy Dragon Eggs when passing through them.
 * The writer of the Minecraft comic WonderCraft, Samcube, was requested by Mojang to create official Minecraft posters for possible purchase. In part of these works, one can see an area with an Ender Dragon and a chicken on top of a Huge Mushroom. In the same scene is a purple, egg-shaped block like entity near the chicken - this was the Dragon Egg.
 * The achievement “The End.” features a Dragon Egg as its icon. Its icon used to be a Monster Spawner block in the 1.9 pre-releases 3/4/5, due to the lack of Dragon Eggs at this time.
 * When hit with Flint and Steel, a Dragon Egg might break with one hit or teleport and appear in a new position, but still broken.
 * Dragon eggs are one of the few blocks that cannot be obtained through the creative mode inventory.
 * In creative mode, if you obtain an egg as a resource, it is treated as an unlimited block like everything else in your inventory. You can then place Dragon Eggs infinitely.
 * Dragon eggs emit dark purple particles every so often.
 * Dragon eggs are the only mob drop that does not count as a renewable resource. This is because the Ender Dragon is currently the only mob that spawns only once per game.
 * The dragon egg can be considered the most rare block because it's unique.