Minecraft: Xbox 360 Edition

You can get this achievement and "You Need a Mint" if you bring along some glass bottles in addition to your needed supplies to collect the Dragon's Breath. If you follow this guide and do that then you'll have:



You will need 16 Eyes of Ender, which are crafted from ender pearls and blaze powder. In the Elytra tutorial world, the end portal is empty. All 12 blocks need Eyes of Ender for the portal to work. The extra 4 are for the End crystals.

Getting Ender Pearls:
There are Cleric villagers, the purple-robed ones, in the village at x=107, y=81, z=-215.
Mine out a few of the gold blocks on the tall towers near the Elytra. These have a high value when traded to the villagers. Also, mine out some emerald blocks. Make these into gold ingots and emeralds respectively. Emeralds are needed to purchase the Ender Pearls.
When you give a cleric villager enough gold or trade with them enough they will take on a green sparkling effect. If you do this enough, they'll have Ender Pearls. If they run out of ender pearls, just trade them more gold. Do this until you have at least 16 Ender Pearls. You can also get ender pearls by killing Endermen.
They're found in the Aquatic Update tutorial as well.

Ghast Tears:
4 Ghast Tears are found in the brewing area of the tutorial. This is all you need.

Getting Blaze Powder:
10 blaze powder piles can be found in the brewing area of the tutorial. You will need at least 6 more. 2 piles of Blaze powder can be made from 1 Blaze rod. Blaze rods are obtained by killing Blazes in the Nether. An activated Nether Portal can be found at x=132, y=50, z=-119. Actually, you can just go out and come back to a freshly stocked chest full of them.
KinectKid333 says:
Thank you for the great guide! However, you don't need to go through the trouble of killing blazes for more blaze powder. There is a feature in the tutorial world where if you take items from a chest then go to a different area, they will respawn in the chest. Instead of killing more blazes, I just went to the farming section of the tutorial and came right back and there was 10 more blaze powder waiting for me in the chest!

Glass:
You need 28 glass blocks. Glass is made by smelting sand in a Furnace. You will need to gather 28 sand blocks from beaches, deserts, or other places. Then you must smelt them in a Furnace. If you can obtain a bucket of lava, use it. Using this type of fuel will net you this achievement if it's your first time doing so:

This fuel lasts for a very long amount of time, so you don't have to waste wood blocks, planks, or other burnable supplies.

End Crystals:
An End Crystal is made from 7 blocks of glass, 1 Ghast Tear, and 1 Eye of Ender. You will need 4.

Fighting and Respawning the Ender Dragon:
Note: Make sure you save before entering the End Portal so that you can reset the End if you can't destroy the End Crystals. If you entered the End, can't destroy the End Crystals and can't go back, you can still reset the End. Doing so will teleport you with all your supplies back to the main tutorial area.

An End Portal is found at x=172, y=30, z=117. Place 12 Eyes of Ender in the holes of the blocks to activate the portal and enter. You'll have to dig you're way up out of a room at first. Now for the Ender Dragon fight. Use stacks of blocks such as dirt or stone to climb to each tower. Make sure you avoid the purple balls or expulsions of Dragon's Breath the dragon sends at you, as they can damage you. You can also collect the Dragon's Breath in glass bottles. Make sure you stand at the edge of the pools of the substance so you don't get damaged. When you destroy an End Crystal, the resulting explosion will push you. A good technique is to jump on top of an End Crystal before you destroy it since this will send you upwards and prevent you from falling off the tower. Another technique is to run towards the End Crystal while destroying it to counteract the explosive force. You can also place blocks around the tower tops, around the whole square or just in the direction you're pushed to prevent you from falling if you have time. It takes some practice with timing and technique to get it right. Once you get used to it, you'll be able to consistently do it. Save after each crystal is destroyed in case of any mistakes. Once you destroy all of the End Crystals, the dragon can't heal anymore. Every once in a while it will hover near the central square of bedrock. You can use your sword to hit it. If you have a bow and some arrows, you can hit it at other locations as well.
Neptune Diamond says:
In the new aquatic update the portal is at x = 25 Y= 9 and z = 30.
In front of the huge creeper statue, just dig straight down.

Once you kill the Ender Dragon, place an End Crystal on the central block of each of the four sides of the portal. These will automatically restore all destroyed End Crystals and respawn the Ender Dragon, netting you this achievement:


Trainerx says: You can also use snowballs to take down end crystals. The higher ones are a bit harder to hit, but snowballs are a lot easier to get a lot of than arrows.

UPDATE: 4/14/2019
-Solution still works, but the Tutorial world is now completely different. Will look for new End Portal location soon, and will modify solution later, so please stay tuned!

Okay, I have discovered it by placing four End Crystals on all four sides of the exit after defeating the Ender Dragon. Quadrants for the End in the Elytra Tutorial World, as Sasha has pointed out, are X: 209, Y: 65, Z: 89. You can fall down in the cave because there's water you can jump down into to break your fall and prevent you from dying.

To make an End Crystal, you need to get 7 Glass Blocks, 1 Eye of Ender, and 1 Ghast Tear. You need four, which is the sum of 28 Glass Blocks, 4 Eyes of Ender and 4 Ghast Tears.

Glass Blocks - Can be obtained by trading with a Librarian Villager, or you can save all the Emerald hunting for shoveling up 28 pieces of Sand and putting it in a Furnace.

Blaze Powder and Ghast Tear - You can easily get both the Ghast Tear and Blaze Powder from the Potion Brewing area, so I recommend getting it from there. 4 of both items are all you need.

Ender Pearl - All that's left is the Ender Pearl, which you can get by killing Endermen or by trading with Cleric Villagers (villagers that have purple clothing). I advise trading with said Villager to save time looking for Endermen (Iron Pickaxe required for mining the Emerald rings). If possible, you can also trade with a Tool Smith (villagers that have a black apron) and you can get a Sword with a Looting Enchantment so that will increase your chances of getting Ender Pearls from killing Endermen in the Nether or in the Mineshaft (in the underweater tunnels in the southwestern part of the map. Can also look for them underground).

Using a Crafting Table, make the 4 Eyes of Ender in the Tools and Weapons tab. Move over to the Mechanisms tab and you'll see a pink diamond-like shape - that's the End Crystal. Make the four of them and then travel to the End. Head to the exit portal and then place the End Crystals on all 1X3 Bedrock sides (NOT the 1X1 Bedrock pieces). Once you place the last one, the Enderdragon will begin respawning. Once it appears, achievement unlocked.

NOTE: If you're going to vote negativley, please tell me why so I can improve this solution.

EDIT: From what a few people are saying in the comments, they are seeing no Endermen in the Nether. If you don't find any, just explore in different portions of the Nether. It might take you quite some time, but they are there, trust me. Calex also revealed one of the two Nether Portal loctions in the comments as well. Quadrants for the second one are X: -252, Y: 85, Z: 194. Nearby the underwater tunnels in the southwestern part of the map. You're gonna be fighting Ghasts by looking around, too (I recommend bringing a Bow along so you can take them out for safer purposes. Get Arrows from killing Skeletons, which you can also find in the Nether and are mostly found in the Nether Fortress part), as it's more 'open' than the Fortress part.

IMPORTANT: It's best if you save your game BEFORE you enter the End Portal because if you find yourself unable to destroy the End Crystals when fighting the Enderdragon, you'll have to exit the world without saving and then go to the World Options to reset the End. You should now be able to destroy the End Crystals when fighting the Enderdragon. If it doesn't work, keep on trying.