The snallygaster is the horrifying result of experiments with the Forced Evolutionary Virus. According to documentation found at the West Tek research center near Huntersville, West Virginia, the snallygaster was a creation of the Advanced Mutations lab during the Phase 2 project caused by the introduction of the FEVS-006443 combination strain. Originally dubbed subject AM52, the experiment was noted as a success on October 14, 2077.
The snallygaster is a quadrupedal creature. It has two arms with three claws each, of which one is an opposable thumb, and two small limbs on the back of its body, which it usually uses to support itself while sitting. It has no proper face, but has a mouth with a long tentacle-like tongue covered in an acid and has multiple eyes along its back. A snallygaster will use its tongue like a whip up close and spit balls of acid at a range. The snallygaster has at least 40 eyes, two rows of teeth and thorns on its back.
It has been described as being "a dragon-like demon that haunts an area outside of neighboring DC."
Snallygasters can be found in the high-level zones resulting from nuclear weapons strikes. They are found in great numbers in parts of the toxic valley and savage divide, often found in small packs of 2 to 4 individuals.
The Snallygaster follows the idea established in other Fallout 76 monsters in that it is based on local legend. However, the legend of the Snallygaster is more within the area of Frederick County, Maryland. The snallygaster is said to be a dragon-like beast and its first sighting happened in the 18th century by German immigrants. It was described as half-bird and half-reptile with a metallic beak with razor sharp teeth and occasionally said to have tentacles. The earliest stories claim that this monster sucked the blood out of victims. Seven pointed stars reputedly kept the monster at bay, some of which can still be seen painted on barns in the area.