Ender Dragon

The Ender Dragon is a "boss" mob that appears once in The End, but could originally be spawned in the Overworld as a test in the 1.9 pre-release 5. In 1.9 pre-release 5 on creative mode, Ender Dragons could be spawned by right clicking with a Golden Sword in hand. At first, Notch stated that they would be invulnerable, but later denied this. They swoop at the player, destroying any blocks it passes through except obsidian, bedrock, or End Stone. In Pre-release 6, one Ender Dragon appears in each world's End and can be fought and killed. After an Ender Dragon is killed, it will create an exit portal with a dragon egg on top. The Ender Dragon also drops a large number of Experience Orbs -about 72 levels worth- upon defeat. In the 1.0.0 update, the exit portal leads to the Minecraft credits. It is possible to get the wither to fight it, but the wither will probably try to attack the endermen if near.