How to Create a Random Mini-Boss With a Boss Bar

The Goal

A mini-boss is a mob that spawns rarely, has boosted stats, wears gear, and shows a boss bar so the player knows they are in for a fight. The mod supports all of these pieces.

Building the Mini-Boss

1. Pick a base mob, for example a skeleton or a vindicator.

2. Create a new preset entry for it rather than editing the default, so normal spawns stay normal.

3. Give the preset a low spawn chance so it only appears occasionally.

4. Boost health, attack damage, and armor through the attribute section. Add potion effects like strength or regeneration for extra threat.

5. Equip it with enchanted gear in the equipment section.

6. Enable the boss bar option for this preset and give it a display name.

7. Optionally restrict the preset to certain biomes or dimensions so it only shows up where you want it.

Testing and Tuning

Spawn the mob manually in a test world and fight it. If it dies too fast, raise health or armor. If it one-shots you, lower attack damage. Adjust the spawn chance last, since that controls how often players actually meet it.