The Underworld-1.4.0-fabric-1.21.8.jar is a beta file of the Minecraft mod The Underworld - Extra Dimensions Series for Fabric, made for Minecraft 1.21.8. It was published on July 20, 2026 and is 1.3 MB in size. Pre-release builds can contain bugs — back up your world before installing. For the full description, screenshots and every other version, visit the The Underworld - Extra Dimensions Series mod page.
How to install: Put the .jar into the mods folder (.minecraft/mods) and start Minecraft with the matching mod loader profile.
