Dragon Egg

The Enderdragon Egg is an item first mentioned by Notch on the 27th of October, 2011 on which Notch is supposedly working before the release. As this particular egg shares it's name with the enderdragon it is well possible these two are related, however very little information has been made available on the purpose of the egg thus far.

Trivia

 * As of 1.9 pre-release 5, enderdragons drop a single block of obsidian. Given the similarity between the names Enderdragon and Enderdragon Egg, the lack of use for a single obsidian block to the player and the mentioning of the enderdragon egg, it is possible that the dropped obsidian block is merely a placeholder for a yet to be implemented enderdragon egg.
 * It is unknown what purpose the egg will serve and if the egg will be an item or block entity at all. Notch and Jeb may have silently hinted towards having rideable dragons available in the game although no further confirmation has been given about this idea.
 * Notch stated there will only be one enderdragon in The End . Therefor it may be possible that the egg will serve as some means of spawning a new enderdragon in the world or The End realm, but such a purpose would remain mere speculation until more information about the egg has been revealed.