While Fallout 4 has a new weapons system focusing on Legendary enemy spawns and random drops, as it turns out, there are still a few special items in static locations around the Commonwealth. This one is particularly special, as it does not only a ton of damage, but also is part of Fallout’s ongoing references to HP Lovecraft.
In Fallout 3, the Dunwich Building, which was the office building of Dunwich Borers, had been taken over by a strange force unearthed during drilling. Later, the Lone Wanderer is tasked with returning a mysterious book known as the Krivbeknih to an obelisk in the building’s basement, and encounters a man who went crazy under the influence of its power.
In Fallout 4, the Dunwich Borers have a quarry in the northeast section of the map. Wipe out all the Raiders to reach the very bottom of the quarry, then find a door leading to another section of the site where further excavation has occurred. Once you get through the levels of this area and reach the very bottom, you will find a site with a pool of water. Swim to the bottom, then to the left and up, to find this weapon, Kremvh’s Tooth. You can see the general location of the pool in the screenshot of its position on the Pip Boy local map, below.