Aether

Aether is a Minecraft mod which adds a new dimension. There are several different forms of this dimension, usually based on the overworld, but sometimes like the End. Usually they contain mobs from the overworld, but with slightly different behaviours or textures. The Aether's name is based off the Nether, despite the Aether not looking like the Nether in any mods. The portal to the Aether usually looks like the Nether Portal though.