NotTodayMob
Every Minecraft server administrator knows the frustration. You spend hours crafting the perfect modpack, only to have a handful of problematic mobs ruin the experience. A creeper that shouldn't exist in your custom dimension. A modded creature that spawns too frequently and crashes your server. Or perhaps a specific mob that simply refuses to appear, no matter how many times you search. The usual solutions are clunky: complex datapacks, scripting languages, or invasive world-gen modifications that break other mods. NotTodayMob changes all of that with a refreshingly simple approach.
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. When unwanted mobs try to spawn, the answer is simple: not today.
Why NotTodayMob Stands Out
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. This means you can make adjustments on the fly without regenerating your world or wrestling with conflicting datapack priorities.
The mod supports Forge 1.20.1 and NeoForge 1.21.1, ensuring compatibility with the most popular modded Minecraft versions. Its lightweight design makes it safe for even the largest modpacks, and it is fully server and multiplayer friendly.
Core Features at a Glance
- Block specific mob spawning with exact IDs or wildcard patterns
- Adjust natural spawn frequency using configurable weight multipliers
- Optionally replace or remove matching spawners during chunk loading
- Automatically removes spawn eggs and spawners from player inventories and the world
- Additional fine-grained control for baby variants, supporting vanilla and modded mobs
- 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
If you are looking to streamline your modding workflow, the foxygame.net launcher offers a one-click install for NotTodayMob, bundling the mod with its dependencies and ensuring version compatibility so you can jump straight into configuration without manual file management.
Getting Started: How to Install
Learning how to install NotTodayMob is straightforward. First, ensure you have the correct loader installed for your Minecraft version. For Forge 1.20.1 or NeoForge 1.21.1, download the mod jar and place it into your mods folder. For dedicated servers, the same applies to the server's mods directory. After launching the game once, a configuration file will be generated in the config folder. That is where all the magic happens.
For those managing multiple instances, downloading NotTodayMob through the foxygame.net launcher's add-on catalog keeps everything organized, with auto-updates ensuring you never miss a patch or a compatibility fix.
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 a restart or reload.
Core Behaviour
The blockEntitiesEnabled setting controls whether matching entities are prevented from spawning. It defaults to true. If disabled, all entity blocking rules are ignored. The blockBabyVariants setting controls whether baby variants of blocked entities are also blocked, defaulting to true.
World-Generated Spawner Handling
The worldgenSpawnerRemoval setting controls whether matching world-generated spawners are removed or replaced during chunk loading. If enabled, matching spawners will be replaced using worldgenSpawnerReplacements, or removed if no valid replacement is defined. This setting only applies to world-generated spawners like those in dungeons and structures, and accepts exact entity IDs only.
For example, the configuration worldgenSpawnerReplacements = [ "minecraft:zombie" ] will convert skeleton or spider spawners found during chunk loading into zombie spawners. Existing worlds will be updated as chunks are loaded. Note that 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, avoiding chunk-loading warnings.
Spawner and Spawn Egg Controls
The suppressBlockedEntitySpawners setting defaults to true, preventing matching spawners from being used. The suppressBlockedEntitySpawnEggs setting similarly blocks spawn eggs. If you want the items to exist but still prevent spawning, you can disable these and rely on the entity blocking rules alone.
Inventory and Item Cleanup
The cleanupDroppedItems setting removes spawn eggs and spawners for blocked entities immediately when dropped into the world. The inventoryCleanupIntervalTicks setting controls how often player inventories are checked, defaulting to 10 ticks (half a second). Higher values reduce overhead but delay cleanup.
Blocking Entities
The blockedEntities list defines which entities are prevented from spawning. It supports exact IDs, namespace wildcards, prefix and suffix wildcards, and optional dimension scoping. For instance:
blockedEntities = [ "minecraft:skeleton", "minecraft:*spider", "alexsmobs:*", "minecraft:zombie|dimensions=minecraft:overworld" ]
The blockedBabyEntities list works similarly but only blocks baby variants without blocking their adult counterparts.
Scope Rules to Specific Dimensions
Rules can be limited to specific dimensions using inline dimensions= filtering. This allows you to block zombies only in the Overworld while leaving them unaffected in other dimensions. It works with both vanilla and modded dimensions.
Adjusting Natural and Custom Spawn Frequency
The naturalSpawnWeightMultipliers setting adjusts natural spawn frequency for matching entities. A multiplier of 0.0 disables natural spawning, 0.5 makes them half as common, 1.0 is vanilla behaviour, and 10.0 is the maximum supported multiplier. Weight adjustments apply only to natural spawning, leaving spawner and command-based spawns unaffected.
The customSpawnChanceMultipliers setting adjusts spawn success chance for entities created through EVENT or TRIGGERED spawn types. This is invaluable for mods that use custom event-based spawning, allowing you to reduce or disable problematic spawns independently of natural rules.
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
NotTodayMob works automatically with modded mobs, biomes, custom dimensions, and datapack-driven spawning, requiring no special integration. For server administrators managing multiple packs, the foxygame.net launcher's version compatibility checker ensures that NotTodayMob is always matched with the correct Minecraft and loader versions, eliminating guesswork during setup.
Final Thoughts
NotTodayMob delivers exactly what it promises: predictable, lightweight control over mob behaviour. Whether you are a modpack creator balancing a complex pack or a server admin tired of creeper explosions in your carefully built spawn area, this mod provides a clean, configurable solution. Its runtime application means no world regeneration, and its compatibility with modded content makes it an essential tool for any serious modded Minecraft setup. Download NotTodayMob today and tell those unwanted mobs exactly where to go.