NotTodayMod

Designed with simplicity and performance in mind, NotTodayMob provides configurable control over mob spawning without modifying world generation definitions or biome data. Individual mobs — or entire namespaces — can be blocked entirely, or have their natural spawn frequency increased or reduced using straightforward configuration.

NotTodayMob is intended for modpack creators and server administrators who want predictable, lightweight control over mob behaviour without complex datapacks or scripting.

All changes are applied at runtime and work automatically with modded mobs, modded biomes, and custom dimensions.

When unwanted mobs try to spawn, the answer is simple: not today.

### Latest Update - Version 1. 0. 4

NotTodayMob now includes optional support for controlling baby variants.

The new `blockBabyVariants` setting allows pack creators and server administrators to decide whether baby versions of blocked entities should also be prevented from spawning.

### Features

Block specific mob spawning Adjust natural spawn frequency using configurable weight multipliers Optionally replace/remove matching spawners during chunk loading Automatically removes spawn eggs and spawners from player inventories/in world Additional fine-grained control for baby variants with support for vanilla and modded mobs that expose baby/adult state through standard Minecraft entity behaviour Supports exact IDs and wildcard matching including dimension-specific rule scoping Periodic performance statistics logging Works automatically with modded mobs and biomes No biome or world generation changes required Lightweight and safe for large modpacks Server and multiplayer friendly

###### Note

On Forge 1. 20. 1 and NeoForge 1. 21. 1, matching spawners are first replaced with an inert spawner before being safely removed on a later chunk load.

This staged removal avoids chunk-loading warnings caused by removing block entities too early during world generation.

### Typical Use Cases

Reduce the number of specific mobs in survival gameplay Increase the presence of certain creatures in themed worlds Disable problematic or unwanted modded mobs Balance mob populations in large modpacks Fine-tune difficulty without editing datapacks

### Configuration Guide

NotTodayMob is configured using a small set of server-side settings designed to be predictable and easy to understand. Changes can be made at any time and will apply automatically after restart or reload.

Core Behaviour

###### blockEntitiesEnabled Controls whether matching entities are prevented from spawning.

Default: `true`

If disabled, all entity blocking rules are ignored.

###### blockBabyVariants Controls whether baby variants of blocked entities are also blocked.

Default: `true`

If disabled, baby variants will still spawn even when the adult equivalents are blocked.

World-Generated Spawner Handling

###### worldgenSpawnerRemoval

Controls whether matching world-generated spawners are removed or replaced during chunk loading.

Default: `true`

If enabled, matching spawners will be:

• Replaced using `worldgenSpawnerReplacements`, or
• Removed if no valid replacement is defined

If disabled, world-generated spawners remain unchanged.

###### worldgenSpawnerReplacements

``` toml worldgenSpawnerReplacements = [ "minecraft:zombie" ] ``` ###### Behaviour

• Applies only to world-generated spawners (e.g. dungeons, structures)
• Only accepts exact entity IDs
• Replacement occurs automatically when a chunk is generated or loaded
• Multiple entries can be provided as fallbacks
• If no valid replacement is defined, the spawner is removed instead
• Existing worlds will be updated as chunks are loaded

###### Example

``` toml blockedEntities = [ "minecraft:skeleton", "minecraft:*spider" ]

worldgenSpawnerReplacements = [ "minecraft:zombie" ] ``` Here, skeleton or spider spawners found during chunk loading will become zombie spawners

Spawner and Spawn Egg Controls

###### suppressBlockedEntitySpawners

Controls whether matching spawners are blocked from use.

Default: `true`

If disabled:

• Spawners remain usable
• Entity spawning behaviour still follows blocking rules

###### suppressBlockedEntitySpawnEggs

Controls whether matching spawn eggs are blocked from use.

Default: `true`

If disabled:

• Spawn eggs can still be used
• Entity spawning behaviour still follows blocking rules

Inventory and Item Cleanup

###### cleanupDroppedItems

Controls whether spawn eggs and spawners for blocked entities are removed immediately when dropped into the world.

Default: `true`

Disable this if you want blocked items to exist but still prevent spawning.

###### inventoryCleanupIntervalTicks

Controls how often (in ticks) player inventories are checked for blocked spawn eggs and spawners.

Default: `10`

| Ticks | Actual Time | |---------|-------------------| | `10` | Half a second | |