According to urban legend, the Goatman is an axe-wielding half-animal, half-man creature that was once a scientist who worked in the Beltsville Agricultural Research Center. The tale holds that he was experimenting on goats until one experiment backfired, and he was mutated, becoming goat-like himself. He then began attacking cars with an axe, roaming the back roads of Beltsville, Maryland. A variation of the legend tells of the Goat-man as an old hermit who lives in the woods, seen walking alone at night along Fletchertown Road.
One variation of the story has it that the Goatman was the result of a (very early) DNA experiment conducted by a scientist named Stephen Fletcher, though other variations suggest a more supernatural origin involving the Devil.
According to University of Maryland folklorist Barry Pearson, the goatman legends began "long, long, long" ago and were further popularized in 1971 when the death of a dog was blamed on Goatman by local residents. Pearson says "bored teenagers" keep the Goatman legend alive by repeating the story and suggesting that the creature attacks couples frequenting the local lovers lane, subsequently stirring interest in sites like Fletchertown Road.
Info from: https://cryptidz.fandom.com/wiki/Goatman