The Interloper

The Interloper, also known as the Firstborn of the Wood, is a creature found in Appalachia.

Background
Jeff Lane mentions the Interloper in recorded holotape messages and cultist notes. In the messages, Lane describes the nature of the Interloper's "calling" to himself and other members of the Cult of the Mothman. The Interloper is known to have communicated with the "First Priestess of the Wood," an honored individual who conveyed the creature's messages to the cult's followers.

While previously just a "false memory," the creature's existence was confirmed to Jeff Lane after hearing a tale of the entity "made real" deep underground by a mad storyteller. It is at this point at which Lane describes the Mothman to be merely a creature, more similar to the human race than the Interloper and the "unknowable horrors" hidden within the subconscious mind.

The creature later calls to Jeff Lane in a lucid vision, inviting him deep into the depths of the Lucky Hole Mine. He explains how that although it appears others have also heard the Interloper's call, the entity summons him alone in the end. Lane further states that the Interloper chose him as the "conduit of the unknowable" and how the "hidden reality" will finally become revealed.

According to the series of notes spread throughout the mine, supernatural events occurred as the cultists inhabited the location, including the formation of a water spring. The creature will bleed if struck by the player character and its tentacles occasionally move, indicating that the creature is still "alive," despite its apparent dormant state. A sect from the Cult of the Mothman congregate within Lucky Hole Mine and continue their zealous worship. They kneel before the Interloper with arms raised high, offering human sacrifice and blood-filled jars to the Interloper.

The Enlightened write about the Interloper in the tome False Gods of Appalachia, stating that the faithful should not speak of it, and that, "there is no fouler deceit than one garbed in truth." They are instructed to, "shun its call, for it can bring only darkness."

Characteristics
The Interloper is an immense, dormant creature sprawled in the depths of the Lucky Hole Mine. It appears as a multi-armed humanoid-like figure consisting of a vine or root-like material. The Interloper emanates an eerie, droning hum. A fog surrounds its body, as well as several skeletons, corpses and effigies.

Appearances
The Interloper appears only in Fallout 76.

Behind the scenes
The game files define the creature as an actor mesh and designate it "gutpuker."