The Deep Void

This mod adds a new dimension to explore composed of only a barren wasteland of bones, corpses falling from the sky and mysteries that awaits the player. But be careful of the inhabitants, for they're not really friendly towards visitors.

Curseforge link :

https://www.curseforge.com/minecraft/mc-mods/the-deep-void

To enter this dimension, you must fall in the Void. A hole in the bedrock can be found at the deepest layer of your world at 0,0. Simply jump in and you'll be there. Alternatively, you can also fall in the Void in the End.

Many creatures await in these bone dunes for a prey. One of these creature isn't like the others. It likes to watch from afar, in the dark, and waits for an unexpecting victim to step out of the light. But be careful, the inhabitants aren't very fond of light and will destroy any sources present. Wathever you do, STAY IN THE LIGHT, or you might be this thing's next meal...