Ender Dragon

Health Points	200 ( � 100)
Attack Strength	10 ()
Spawn	The End
First Appearances	Beta 1.9pre4(disabled) Beta 1.9pre6(official)
Network ID	63
Savegame ID	EnderDragon
Drops	The Overworld Portal and Dragon Egg (Directly below it)
Experience	20,000

An Ender Dragon attacks a player while being healed

The portal generated when the dragon is defeated

The Ender Dragon is the first (and currently in the actual game, the only) official boss mob to appear in Minecraft (with the second being the Wither, introduced in pre-release 12w34a). It only naturally spawns in The End. This mob uses the dragon model Notch created, but utilizes a texture more reminiscent of an Enderman, being black and scaly with purple eyes.

 Appearance

The Ender Dragon is a large, black dragon with glowing purple eyes. It is the second-largest mob in the game, only beaten by the unused Giant. It has a few dark gray features, such as the wings and various other parts of its body. Similar to Endermen and Spiders, the Ender Dragon's eyes are visible through darkness, so you can see it coming from anywhere in the End.

 Strategy

Before entering the End, it is very strongly advised that the player first sleep in a bed near the End portal or taking a backup in case they die during the battle. It is strongly recommended that the player should have a full set of iron armor or higher, as any lower will get you easily knocked off The End by the Ender Dragon. Also have a diamond sword along with a bow and 2 to 4 stacks of arrows, or a bow with the Infinity enchantment, but note that the sword enchantment fire aspect and the bow enchantment flame do not work on the Ender Dragon.
Upon entering the End, a purple "boss health" bar appears at the top of the player's screen. This bar indicates the remaining health of the resident Ender Dragon. Each End dimension houses a single Ender Dragon whose health is periodically charged by nearby Ender Crystals. These crystals can be found at the top of Obsidian pillars that dot the landscape. As the healing effect of the Ender Crystals can reverse hard-won damage rather quickly, it is recommended that they be destroyed before the player engages the Ender Dragon.
Destroying an Ender Crystal while the Ender Dragon is being charged by it (indicated by a series of circles appearing between the Ender Crystal and the Ender Dragon) will cause the Ender Dragon to take additional damage instead of being healed. If the player repeats this method for all of the Ender Crysals, then the Ender Dragon will become weak and can be killed with no chance of it regaining health. Even after taking so much damage, it is still stronger than an average mob. Players can destroy an Ender Crystal by either as they would a regular block or by attacking it with a sword, a bow and arrow, snowballs, etc. When destroyed, the Ender Crystal explodes, leaving behind a block of Bedrock.
Defeating the Ender Dragon in creative mode is quite easy, as the player can fly around and easily snipe or attack the dragon with melee attacks without having to worry about getting killed. But you MUST destroy the Ender Crystals as they will continue to heal the dragon even in creative mode. You have to worry about possibly getting knocked off the island because even in creative mode you can still die if you are knocked off the edge into the void.
The most common and easiest strategy to defeat the Ender Dragon is to destroy all of the Ender Crystals before attempting to fight the Ender Dragon, as any damage done to the dragon can be quickly undone by the crystals. Since Ender Crystals explode, an advisable strategy is to shoot arrows or to throw snowballs from a distance so the player does not take damage, then climb up the Obsidian towers with a ladder. This ensures that if the player falls off the tower due to exploding Ender Crystals, that player will be able to grab onto the ladder and not die. (However, it should be noted that the Ender Dragon can and will destroy the player's ladders).
If at all possible, the player should attempt to destroy the Ender Crystals while the Ender Dragon is too far away to detect or charge them. The player can wait for the Ender Dragon to fly near to the edge of the map, then run the other way until the boss's health bar disappears. The player can then safely destroy the Ender Crystals on that end of the map, taking care not to get close enough for the Boss's health bar to reappear. By repeating this strategy a few times, the player should be able to clear out the crystals from all parts of the map.
When the Ender Dragon charges the player, it is directly facing the player. This gives the player a good chance of attacking its head to deal extra damage. But if the player decides to attack it, he/she will have less time to try to avoid its attack. The Ender Dragon will also destroy any block it comes into contact with except Obsidian, End Stone, and Bedrock. Instead of destroying them, the Ender Dragon passes through them. This makes TNT strategies difficult, if not impossible, to successfully execute. The Ender Dragon's swooping melee attacks have a significant amount of knockback if a player is hit by them, often knocking the player off of the platform in the End. The impact of the Ender Dragon's body and wings cause damage to the player, as well as knock back. Because of the Ender Dragon's speed and flight, projectiles are favored over melee approaches. The Ender Dragon's immense health and evasive nature necessitate a large ammunition stockpile. At least 2 full stacks of arrows are recommended since most will miss. Lava is useless, as it is immune to fire damage. Water is also useless, as it will take no damage from water and will destroy the block. Knockback enchantments are useless unless the enchantment is on grade 8 or higher (this is possible in SMP with modifications). Snowballs have the potential to stun-lock an Ender Dragon as its recovery time is slower than the firing rate of snowballs. Snowballs can also damage the Ender Dragon along with other thrown entities, such as Ender Pearls and Eggs. The Ender Dragon will take more damage from a melee attack than a ranged attack. Therefore, the player should wait for it to charge, sidestep, and then attack. Beds, which explode in the End, can be detonated when the Ender Dragon is nearby, causing considerable damage to it. This seems to almost be an exploit and should be avoided. TNT works the same without exploitation.

A dying enderdragon. (Animated)

Once killed, the Ender Dragon will appear to have beams of light spontaneously erupting from its body. It will then explode, dropping enough experience to bring a player from no experience to level 78 (20000 - 10 drops of 1000 experience, one drop of 10000 experience).
If the player brings an enchantment table and 15 bookcases with him/her while killing the Ender Dragon, he/she can set it up after it dies and use it every 30 levels for many high level enchantments. It will also spawn an exit portal with a Dragon Egg on top. Entering the portal will activate a text cutscene that lasts for an average of 8 minutes, 30 seconds. After the cutscene, the player will be teleported to his/her spawn point in The Overworld. The cutscene can be skipped by pressing the Esc key, and will instantly send the player to his/her spawn point/Bed in The Overworld. The player may return to the End after defeating the Ender Dragon, however there will be no new dragon.

This video is about the ENDERDRAGON, it shows you very interesting stuff.