Mystic Realm

This is a biome that is situated in the sky (think of a sky island.) The main ground is made of white wool and is made in the shape of clouds where things like path ways are lined with different colors of stained glass. Naturally generating structures in this biome are four temples that are at the far corners of the biome, these temples have things such as blocks of gold and some chests that contain late game gear such as diamond tools and armor.

This biome only generates after killing the Ender Dragon (as an extra.)

This biome's mobs would consist of the unused mobs and mobs that lost the MineCon vote, this seems strange but there is a fun little reason for this. The Mystic Ream is meant to be the opposite of the Nether and its inspiration (that being Hell) the Mystic Realm would be the "Heaven" of the Minecraft world. Thought it would be interesting if the scrapped mobs that make up his biome are in a way "dead" and this is their afterlife in some way (and this is a clever way to incorporate unused content in away that does not interfere with the main game.).