From The Fog Data Pack Wiki & Guide
wiki.9minecraft.net/from-the-fog-9minecraft-data-pack/
How the From The Fog Herobrine haunting works, the signs he leaves, and how the danger escalates.
Overview
From The Fog is a horror addition that turns an ordinary survival world into a slow-burn ghost story built around the legendary Herobrine. Rather than a boss you fight immediately, Herobrine is a patient stalker who haunts your world over many in-game days. He appears only for a moment, stays at the edge of your vision, and messes with your world while you are away, so the horror builds through atmosphere and paranoia long before anything ever attacks you. Because everything is data-driven, you simply keep playing normal survival and the world grows more haunted around you.