This is about the monster in the game and fanfiction. For the Minecraft : Revenge of the Wither variant, see here.
The Enderdragon, in one fanfiction, was the lord of the End, but he was slain by Steve and the Cyan Shirt League. The Ender Crystals absorbed his soul and trapped it in the End Amulet, making him the last god to be trapped in an amulet. He is a known enemy of The Voice in the Darkness, but he is not a friend of the citizens of Minecraftia. By hypnotizing the Endermen before he was trapped in the End Amulet, he was nearly responsible for invading the Overworld and he is not to be trusted.
In the Wielder Chronicles, written by OutKookDrive and an anonymous author, Herobrine and his sister Lillian are children of the Enderdragon. They had presumably inherited powers from the Enderdragon, such as possesion and speed. However, the Enderdragon is not described as a dragon, or any specific person; he is just mentioned as an insanely powered creature who is angry at Herobrine's death and Lillian's failure, at the end of the series. He then plots angrily. Since the Enderdragon's children are not dragons, it is unknown as to how he had kids.Ender Dragon killed the powerfull Magma Overlord, and in the present Ender Dragon is controlling the MagmaBrine empire.Thats why the blaze rods can be used to craft Eyes of Ender.Ender Dragon is in an alliance of the evil creatures that they are searching for a mystic sword that can let the Ender Dragon to control the Ghouls of the powerfull Kronos( the most powerfull demon).PS: The swords name is The Anihilator.The Ender Dragon is alive because it escaped from the Ender Amulet. PS:ED was not dead just weaker... and his pshysihical form was shapenshifted to an spiritual form.