The Old One
Java mod listed for Minecraft 1.21. Downloads from the MC Java Mods app on Android.
⬇ Download on CurseForgeThe author built this one for Minecraft 1.21.1 on NeoForge. On other versions it may install and then do nothing.
This mod adds a new boss, items, and weapons.
This is a semi-complex mod I cooked up in MCREATOR that adds a new end-game boss into your Minecraft world. It also includes 2 new weapons!
This is a powerful creature that is capable of breaking the toughest of shields!
But in all seriousness, this boss is reaaaalllyy tough. So, use the best gear you can get.
To summon The Old One, you must build a structure like this:

Now, before you go fighting, theres a new sword that you can make to better your chances in battle. But first, we need to make Holy Essence. To make this, smelt a dragon egg like this:
After that, you can make a Holy Diamond Sword by putting a diamond sword and Holy Essence into a crafting table:

Once you've defeated The Old One, you can make an extremely powerful blade, "The Old One's Sword". To do this, put a Holy Diamond Sword and the Old One's Heart into a crafting table like this:

You may use this in your modpacks for a bit of challenge in your journies!
Additions:
New Items (Old One's Heart, Holy Essence, The Old One's Sword, Holy Diamond Sword)
New Mobs (The Old One, Stray Copy)
- Edition: Minecraft Java
- File type: .jar
- Minecraft version listed: 1.21.1
- How to install: Install the matching mod loader (Forge, Fabric or NeoForge) for your Minecraft version. → Download the .jar. → Put it in the .minecraft/mods folder and launch that loader profile.
- Where to get it: Opens on CurseForge — not every file is mirrored on our own servers.
Install steps are the general flow for this file type — How to install Minecraft Java mods & modpacks walks through it step by step.
- Ships as theoldone-1.0.0-neoforge-1.21.1.jar — drop this file into the mods folder
- Download size: 145 KB
- Download link checked 27 Sept 2026 — working
These come from our own check of the pack file, not from the source page.