The Unseen Observer.

The Unseen Observer adds an entity that runs as a background process and monitors how the player behaves. It logs movement patterns, death count and playtime for each world, and that data persists across different worlds. The mod pairs with Metadata Integration, and the author notes it uses the PC hostname, OS username and system clock to trigger events, while the entity can address the player directly in chat. A working internet connection must be available for the mod to run, and its records sit locally inside a concealed file named hidden.dat.

The mod is a psychological horror overhaul for Minecraft 1.20.1 on Forge. It is not a version of the Dweller mod, and its entity does not aim to kill the character. Its goal is to interfere with the player's perception of the game through subtle world triggers, torches that go out, sounds that desync, chunks that update incorrectly and loud screams with cheap jumpscares. The author recommends headphones and a render distance of at least 4 chunks. The Unseen Observer is client and server, and it is released under All rights reserved, so the code is not open source.