Ug-Qualtoth

Ug-Qualtoth is an "alien entity" mentioned in Fallout 3, its add-on Point Lookout and Fallout: The Roleplaying Game.

Background
Ug-Qualtoth is described as a "forgotten god," with those who worship it suggesting that it is not so forgotten after all. It is stated that only the "Screaming Sound of Ug-Qualtoth" can wield power of The Krivbeknih, a book which shares its origins Dunwich Obelisk. Richard Dunwich, founder of Dunwich Borers LLC, and his sibling Constance Blackhall, were worshipers of Ug-Qualtoth and known for their "obsession with the occult." Two of their locations, the Dunwich Building in Washington, D.C. and Dunwich Borers in the Commonwealth, were being used as a grounds to uncover a "great monolith" related to Ug-Qualtoth.

Dunwich Borers LLC
Dunwich Borers LLC was responsible for creating rock-tunneling drills, which were tested within one of their marble quarries. This quarry was the site of an ancient temple dedicated to dark gods, whose adherents practiced human sacrifice. Dunwich Borers LLC's abysmal record of human safety precautions, which often led to employee deaths, is rumored to be an intentional move to "bring eldritch attention and supernatural powers" to corporate leadership by means of modern human sacrifice.

Underneath the Dunwich Building in Washington is an altar related to Ug-Qualtoth next to the Dunwich Obelisk, with all who attempted to investigate it either dying or "scraping together a day-to-day existence." Jaime, a ghoul found near the altar, traveled to the Dunwich Building in search of his father, who discovered a book bound in "odd black leather" and stamped with strange glyphs on an expedition. While he planned to sell it to the scribes of the Brotherhood of Steel, Jaime's father wound up in the Dunwich Building, vowing to return the book "to its source." His body and the book were discovered by Jaime, who noted that his father was turning into "one of the zombies," and that the book was "warm against the stone."

Point Lookout
Constance Blackhall's occultism extended to Point Lookout, where their family was involved in its commercialization during the early 21st century. Constance used their newfound wealth to obtain many archaic texts and artifacts, including The Krivbeknih. Drawing from a small group of devotees, Constance formed a sect dedicated to the book, acting as the priest. Constance survived during and after the Great War, with local legends accrediting her long life to the book prior to being stolen, which coincided with their death.

Constance's descendant, Obadiah Blackhall, also worships Uq-Qualtoth. After discovering the Krivbeknih had made its way back to Point Lookout, he planned to repossess the book in order to restore power to his family back from the local Swampfolk, who think it holds an "occult power." Within their ritual site lies a sacrificial chamber, with the book lying on a ceremonial lectern. Anthropologists postulated that the Swampfolk "have a belief in the occult" and that they pray to the "hitherto unknown entity" of Ug-Qualtoth.

The missionary Marcella traveled from the Commonwealth to Point Lookout to spread her faith. While there, Obadiah solicited her to find the book, which she investigated further, recognizing its name and declaring that it must be destroyed. During the quest The Dark Heart of Blackhall, the Lone Wanderer is tasked with destroying the book by pressing it against the Dunwich Obelisk next to the Ug-Qualtoth altar underneath the Dunwich Building.

Appearances
Ug-Qualtoth is mentioned in Fallout 3, its add-on Point Lookout and Fallout: The Roleplaying Game.

Behind the scenes

 * In the Fallout 3 game files, there is unused bloody drawing of the Ug-Qualtoth statue from the Dunwich Building.
 * The quote "Ug-Qualtoth knows the gate. Ug-Qualtoth is the gate. Ug-Qualtoth is the key and guardian of the gate!" from the Fallout 3 Official Game Guide is a reference to the quote, "Yog-Sothoth knows the gate. Yog-Sothoth is the gate. Yog-Sothoth is the key and guardian of the gate. Past, present, future, all are one in Yog-Sothoth." from the H.P. Lovecraft book, The Dunwich Horror.