Only Zombies Spawn
Imagine a Minecraft world where the night is ruled by one enemy and one enemy only. No skeletons rattling in the dark, no creepers sneaking up behind you, no spiders dropping from cave ceilings. That is exactly what Only Zombies Spawn delivers. This lightweight add-on rewrites the hostile mob spawning rules so that every monster that tries to appear is instantly swapped for one or more zombies. The result is a focused, tense, and surprisingly fresh survival experience that turns the familiar night into a relentless undead siege.
What Only Zombies Spawn Actually Does
At its core, the mod intercepts hostile mob spawns and replaces them with zombies. When any non-zombie monster attempts to spawn, the game cancels that spawn and places zombies instead. This applies across a wide range of spawn sources, including natural overworld spawns, mob spawners in dungeons and mineshafts, chunk generation, structure-based spawns, and even patrols. In practice, that means you will not stumble into a pillager patrol or a wandering group of hostile mobs — you will meet a crowd of zombies instead.
Two important exceptions keep the game's progression intact. Bosses are excluded from replacement, so the Ender Dragon and the Wither still spawn normally. This means you can still complete the main story content while the rest of the world is overrun by the undead.
Key Features at a Glance
- Spawn Replacement: Every hostile mob is replaced with zombies, from the surface to the deepest caves.
- Wide Coverage: Works for natural spawns, mob spawners, chunk generation, structures, and patrols.
- Boss Exclusion: Ender Dragons and Withers spawn normally, preserving vanilla progression.
- Spawn Multiplier: Configure between 1 and 40 zombies to appear in place of a single replaced mob.
- Persistence Inheritance: If the original mob was set to not despawn, such as through a Name Tag, the replacement zombies inherit that persistence.
If you are ready to try it, you can download Only Zombies Spawn from the official mod pages and drop it into your mods folder. Players who prefer a smoother setup often grab Only Zombies Spawn for Minecraft through the foxygame.net launcher, which keeps the add-on in its catalog and applies updates automatically so your zombie apocalypse never breaks after a game patch.
Configuration and the /ozsconfig Command
Customization is handled through an in-game configuration GUI. Simply type /ozsconfig to open it and adjust the settings to fit your world. The configuration file is saved at config/onlyzombiesspawn.properties, so you can also edit it manually if you prefer.
Available Settings
- Allowed Mobs (allowedMobs): Specify a list of mobs that should spawn normally without being replaced.
- Disabled Dimensions (disabledDimensions): Choose dimensions such as The Nether or The End where the mod's effects are turned off.
- Zombie Spawn Multiplier (zombieSpawnMultiplier): Set how many zombies appear per replacement, from 1 to 40. The default is 1.
The multiplier is where things get interesting. Setting it to 5 or 10 turns a single creeper spawn into a small horde, which dramatically raises the difficulty for experienced players. If you want a more manageable challenge, leave it at 1 and let the mod do its quiet work in the background.
Supported Versions and Loaders
Only Zombies Spawn supports a broad range of modern Minecraft versions across three major loaders. For Forge, you can run it on 1.18.2, 1.19.2, and 1.20.1. NeoForge users are covered on 1.21.1, 26.1, and 26.1.2. Fabric players can install it on 1.20.1, 1.21.1, 26.1, and 26.1.2. This wide compatibility makes it easy to slot into almost any current modpack without worrying about version conflicts.
How to Install Only Zombies Spawn
Installation follows the standard modding routine. First, make sure you have the correct loader installed for your Minecraft version. Next, download Only Zombies Spawn from a trusted source and place the .jar file into your mods folder. Launch the game with the matching profile, and the mod will activate automatically. If you want to verify it is working, wait for nightfall and watch what spawns around you — if skeletons and creepers are gone, the mod is running. To fine-tune behavior, open the config with /ozsconfig and adjust the multiplier or allowed mobs list.
Who Should Play With This Mod
Only Zombies Spawn is ideal for zombie-themed worlds, custom modpacks, and survival challenges. It is especially fun for players who want a simplified but more intense combat loop, since you only need to prepare for one type of enemy. Builders appreciate it too, because the predictable threat makes large projects less chaotic. Whether you are crafting a hardcore undead survival series or just want a spookier night, this mod reshapes the game in a way that feels both familiar and completely new.
Final Thoughts
Only Zombies Spawn proves that a small change can transform an entire playthrough. By replacing every hostile mob with zombies, it creates a consistent, atmospheric challenge that rewards preparation and smart base design. With flexible configuration, boss exceptions, and support for Forge, NeoForge, and Fabric across multiple versions, it is an easy recommendation for anyone craving an undead-focused Minecraft experience. Give it a try, crank up the multiplier, and see how long you last when the whole world shuffles toward your door.