This is a feature allowing players to customize creatures spawned within 100 days.
Players can modify the configuration file in the config folder.
Configuration Content:
-
List of entity registry names (e.g., "minecraft:zombie", "minecraft:creeper"). Spawns entities sequentially in this order. entities = ["minecraft:zombie", "minecraft:creeper"]
-
Days between Boss spawns (Min: 5, Max: 100, Default: 10)
days_interval = 10
-
Whether the Boss spawn feature is enabled
enabled = true
When an entity spawns, you can open the chat bar and click the teleport button to be transported to its location.

Entities will spawn in safe zones—open spaces without obstructions—to prevent phasing into blocks or getting stuck.
This mod supports cross-dimension spawning and works with dimensions from other mods.
In most dimensions, if a safe zone cannot be located, the entity will spawn three blocks above the player's head.
If you wish to disable this feature, you may use commands:
Enable spawning: /100dayboss true
Disable spawning: /100dayboss false
How to Install Custom 100-Day BOSS (Mod)
Custom 100-Day BOSS by Mioki_ is verified for Forge, Neoforge across Minecraft versions 1.18.2, 1.19.2, 1.20.1, 1.21.1 (latest release: 1.4.0, file size: 129 KB). Follow the steps below to install it safely from ModCraft.tv:
- Click the Download button above and select your Minecraft version (1.18.2, 1.19.2, 1.20.1, 1.21.1) and platform (Forge, Neoforge).
- Make sure you have the compatible loader or environment installed for Forge, Neoforge.
- Move the downloaded Custom 100-Day BOSS file into your Minecraft
.minecraft/modsfolder and launch the game.
All Versions
+ Add Version2. Fixed the issue where Boss health bars could not load properly when players moved away from the entity and returned to its vicinity
2. Fixed the issue where Boss health bars could not load properly when players moved away from the entity and returned to its vicinity
2. Fixed spawning failure in dimensions added by other mods
3. Fixed Boss health bars persisting after dimension changes
4. Fixed Boss health bars persisting when players move too far away
5. Fixed accelerated spawn timers in other dimensions
2. Fixed spawning failure in dimensions added by other mods
3. Fixed Boss health bars persisting after dimension changes
4. Fixed Boss health bars persisting when players move too far away
5. Fixed accelerated spawn timers in other dimensions