Spawn Mobs Active
by Icon
Spawn Mobs Active is a Fabric world generation mod that controls which mobs can spawn, using one configurable JSON rule list.
What it does
Rules are read from a single JSON file and checked from top to bottom for each spawn attempt. The first rule whose conditions all match decides the outcome: ALLOW lets the mob spawn, and DENY blocks it. If no rule matches, the default action applies, which is ALLOW and matches vanilla behaviour. Each rule holds the conditions that must be true plus one action, and a field left out is ignored, so the rule applies everywhere for that field.
Conditions cover the mob type, its spawn source, the dimension (Overworld, Nether, End or modded dimensions), height limits such as minY and maxY for great caves, light level and sky visibility, and biome. Mobs can be blocked one at a time by identifier, such as minecraft:creeper, or in whole groups by category. Modded mobs are covered by the category filters. Servers that run it need every player to install it too. It is published for Fabric only, with 1.0.0 as the latest file, and is licensed under All rights reserved, so it is not open source.
Key features
Mob and category rules
Block or allow a single mob by identifier, or a whole category such as MONSTER, CREATURE or AMBIENT.
Spawn source filter
Rules can target the natural spawner, structures, patrols and other spawn sources separately.
Dimension and height filters
Limit a rule to the Overworld, Nether, End or a modded dimension, and to a height band such as cave-only zombies.
Light and biome filters
Match on light level, sky visibility, surface or underground placement, and the biome where a spawn attempt happens.
Chicken jockey options
Dedicated options control chicken jockeys, so they can be blocked without touching other mobs.
Compatibility
Latest build for each game version and loader.
1.21.x11 of 11 versions with builds
Only full game releases are shown. This mod publishes no snapshot builds.
How it compares
Nocreepers is a server-side only Fabric mod, released under All rights reserved, and is published for 1.21.11. Spawn Mobs Active runs on client and server and is published for Fabric. Better Pillager Patrols is a Fabric mod under the MIT License for 1.21.11, where the server needs it and the client is optional, while Mob Rate is an MIT-licensed client and server Fabric mod for 1.21.11 – 26.2.
| Mod | Loaders | Game versions | Environment | Updated |
|---|---|---|---|---|
| Spawn Mobs Active | Fabric | 1.21.1 – 1.21.11 | Client and server | 2026-06-09 |
| Nocreepers | Fabric | 1.21.11 | Server-side only | 2026-04-24 |
| Better Pillager Patrols | Fabric | 1.21.11 | Server required, client optional | 2026-04-29 |
| Mob Rate | Fabric | 1.21.11 – 26.2 | Client and server | 2026-09-12 |
Questions
Does Spawn Mobs Active need Fabric API?
Does the client need Spawn Mobs Active?
How is the rule list written?
Which Minecraft versions does it support?
In the catalog
Spawn Mobs Active is one of 8,515 World generation mods on ModsFinder, and one of 4,027 World generation mods for Fabric. 19,862 mods support Minecraft 1.21.11.
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What the author says
Spawn Mobs Active is a lightweight, fully configurable mob-spawning manager for Fabric 1.21.1. With a simple rule list you decide exactly which mobs may spawn and which are blocked — by mob, category, spawn source, dimension, height, light level, and biome. No commands or coding required: everything lives in one easy…
Official listing
- Modrinth page
- modrinth.com/mod/spawn-mobs-active
- Owner
- Icon
- Published
- 2026-06-09
- Updated on Modrinth
- 2026-06-09
- Facts verified
- 2026-10-15