Not unlocking in Update 1.1!https://www.dropbox.com/sh/qeswcgkt6pah7aa/AACrIRqqZB5OrysSM...Note: Host only. You can not unlock this achievement by joining yourself or someone else on a different device.
In this world, kill the ender dragon, then take the teleporter, and press skip to skip the credits. This will take you back to the main world. Then, head over to the area in the back where it says update 1.0.
In here, go to the left in the back. Make sure the difficulty is set to easy. Then eat a golden apple, and let the shulkers (purple creatures) attack you. I've made a small line of cobblestone against the wall to let you see where you will reach 50 metres.