ModsJava
A-90: The Reaction Entity
Java mod listed for Minecraft 1.21. Downloads from the MC Java Mods app on Android.
⬇ Download on Modrinth
Adds the A-90 entity from Roblox DOORS (The Rooms) into Minecraft.
How it works:
- Warning: A-90 appears on your screen with a glitch sound.
- STOP Sign: When the red STOP sign appears in the center, freeze immediately. Do not walk, jump, or move your mouse.
- Punishment: If you move during the STOP sign, A-90 attacks with a jumpscare, dealing 85% damage. Continuing to move results in instant death.
- Commands:
/a90 spawnto summon,/a90 stopto cancel.
Quick facts
- Edition: Minecraft Java
- File type: .jar
- Minecraft version listed: 1.21.11
- How to install: Install the matching mod loader (Forge, Fabric or NeoForge) for your Minecraft version. → Download the .jar. → Put it in the .minecraft/mods folder and launch that loader profile.
- Where to get it: Opens on Modrinth — not every file is mirrored on our own servers.
Install steps are the general flow for this file type — How to install Minecraft Java mods & modpacks walks through it step by step.
File checked by MCModsHub
- Ships as A90.jar — drop this file into the mods folder
- Download size: 603 KB
- Download link checked 21 Oct 2026 — working
These come from our own check of the pack file, not from the source page.