Mob Effects Modifier
Mob Effects Modifier lets server owners and players assign potion effects to mobs through an in-game GUI, with a spawn schedule and timed effect updates.
What it does
A configuration screen filters specific mobs and assigns them potion effects. Effects can be applied as mobs spawn, or added and removed on custom intervals, so a timer can refresh or drop an effect over the course of a world. Changes are made in the GUI rather than by hand, although the settings can also be edited in the config file.
The mod is a Forge addition for Minecraft 1.20.1 only, with one release, 2.0.0, dated 2026-07-03. Client and server both run it, so the server and every player need it. Editing the config and opening the menu require admin permission, and the effectmenu commands cover group and reload actions. The code is open source under the MIT License.
Installation needs nothing else beyond Forge for 1.20.1. The mod is a Mobs category entry with a Utility tag, and it sits among 4854 other Mobs mods that have Forge files for 1.20.1, so its scope is narrower than general mob overhauls.
Key features
Filtered mob selection
Specific mobs are chosen through the GUI, and only the selected ones receive the assigned effects.
Spawn-time effects
Mobs can gain chosen potion effects as they spawn, so each new mob arrives already affected.
Timed effect intervals
Effects can be added or removed on custom intervals, keeping effects active for set periods of time.
Group and reload commands
An effectmenu group command and an effectmenu reload command manage the configured setup from the server console or in game.
Gallery
Compatibility
Latest build for each game version and loader.
Only full game releases are shown. This mod publishes no snapshot builds.
Use cases
Tuning a survival server
A server owner can make certain hostile mobs stronger or weaker at spawn, using the GUI instead of editing files.
Timed challenge areas
Effects that are added and removed on intervals can mark periods of higher danger in a map or event.
Who it’s for: Server owners who want to change how specific mobs behave without writing code, and players who run single-player worlds with Forge 1.20.1 and want the same control.
How it compares
CraftMobs is server-side only and open source under the MIT License, with files for 1.18 – 1.20.4, so it does not need a client install. HeightLimiter is server-side only, open source under the Mozilla Public License 2.0, and published for 1.20.1 only. Mob Catalog runs on client and server and is open source under the MIT License for Fabric and Forge on 1.20.1.
| Mod | Loaders | Game versions | Environment | Updated |
|---|---|---|---|---|
| Mob Effects Modifier | Forge | 1.20.1 | Client and server | 2026-07-03 |
| CraftMobs | Forge | 1.18 – 1.20.4 | Server-side only | 2025-01-03 |
| HeightLimiter | Forge | 1.20.1 | Server-side only | 2025-11-04 |
| Mob Catalog | Fabric and Forge | 1.20.1 | Client and server | 2024-04-25 |
Questions
Does Mob Effects Modifier need to be installed on both sides?
Which game version and loader are supported?
Who can open the configuration menu?
In the catalog
Mob Effects Modifier is one of 11,058 Mobs mods on ModsFinder, and one of 6,527 Mobs mods for Forge. 34,764 mods support Minecraft 1.20.1.
More from Cyanhana_Neko
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What the author says
一个 Minecraft Forge 模组，允许你自定义生物的药水效果。可以让生物生成时自带效果，或者定时添加/移除效果，所有配置通过游戏内 GUI 完成，无需编辑配置文件。 > A Minecraft Forge mod that lets you customize mob potion effects. Give mobs effects on spawn or add/remove effects on a timer — all configured through an in-game GUI, no file editing required.
Official listing
- Modrinth page
- modrinth.com/mod/mob-effects-modifier
- Owner
- Cyanhana_Neko
- Published
- 2026-06-29
- Updated on Modrinth
- 2026-07-03
- Facts verified
- 2026-10-15