Experiments with recombinant strains of FEV at the West Tek research center in Appalachia produced numerous failed mutations, with two exceptions. The first of these was FEVS-006443 from October 14, 2077, a Phase 2 combination strain that combined traits that resembled a number of different species. The results were considered disturbing by the scientists but provided valuable insights as to the capability of recombinant FEV. Notable changes included a number of ocular organs along the enlarged upper torso, a second set of arms ending in clawed digits, and a large sickle-shaped claw on each inner toe. The living, stable, and functioning subject was sustaining itself normally (a major accomplishment for the program) and was planned for release in Huntersville after the subsequent experiment matured. The mutant was never returned to the area until January 3, 2078, when it escaped containment and the facility. The mutant procreated, leading to the emergence of snallygaster mutants across Appalachia. The horrifying result of experiments with the experimental Forced Evolutionary Virus, has six legs, numerous eyes along its back, and an extended tongue covered in acidic goo that can rapidly take down any survivors.
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 are almost exclusively found around highly toxic or irradiated areas. They are usually in groups of 2-4. When provoked, they will spit a ball of toxic slime from the mouth, dealing poison damage. They will then run up to the player character and use a melee attack, either scratching or hitting the player character with their tongue.
When the snallygaster uses its toxic spit attack, it will remain on the ground for a short amount of time. Pressing the button to pick it up will result in you having the spit attack explosion in your inventory, despite not getting the pop-up to pick it up. This strange ability is shared with attacks done by a behemoth.
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.
The name Snallygaster derives from "Schneller Geister", which is German for "Quick Spirits".