excalibur-1.0.0-universal.jar is a release file of the Minecraft mod Excalibur: The Mighty Sword for Forge, made for Minecraft 1.12.2. It was published on September 29, 2019 and is 0 MB in size. For the full description, screenshots and every other version, visit the Excalibur: The Mighty Sword mod page.
How to install: Put the .jar into the mods folder (.minecraft/mods) and start Minecraft with the matching mod loader profile.