Somebody?

Somebody is in the Darkness Analog Horror
By TheWise

This mod has been seen in many famous MC youtubers videos, for example One Last Times video (click)

This is a simple, but eerie analog horror mod, which adds strange invisible entities with earie name tags to your world. These entities will follow you until you notice them. Once you notice them, they will either disappear inflicting a random effect such as darkness, naseau or blindness, or attack you.

The entities are programmed to follow you, and will follow and stalk you outside your house (from a distance), in your caves and all over your world. 

This mod also adds distorted cave noises to your game to increase the feeling that you are being watched.

(Config) to configure spawn rates on this mod run the following command in chat:
/config showfile somebody COMMON
We recommend using the Configured (click here) mod for easier access from chat configuration file (optional)

(Spoilers) Entity Variations

Baseline Mod Developer: Alexander25
Mod Expansion Developer: TheWise