I know by the sound of the name you're already declaring this as bull shit, but trust me, you have to see it to believe it. Let me tell you the story. I was playing GTA Online and I was talking to this guy I just met. He too, was a myth hunter so we were talking about GTA V myths when he told me he discovered a new one. He said that he once saw the "Goatman". When I first heard him I thought he was full of B.S. but I entertained him and let him take me to the place where he claimed he saw it. He drove me to an old bridge. Its on that trail that leads to Cape Catfish. So I looked around and it looked pretty ordinary - just a bridge built over a dried streambed. He said he was driving down the road (in singleplayer playing as Michael) when he saw a figure in his headlights. He turned them to high beams and saw a horrifying goat humanoid. He quickly took out his phone and took a pic and uploaded it to the R* social club. He said by then it ran under the bridge and towards the ocean. By the time he reached the railing he said it was gone.
So I then went on the R* Social Club to see this pic. When I saw it I was flabbergasted. There is no doubt in my mind that this isn't real. Afterwards I looked more into what the Goatman is and it turns out there is a real legend. The Goatman is a cryptic that is said to inhabit an old bridge in Maryland. The real life bridge looks identical to the one in GTA V. I looked more into this relating to GTA V and came up with a video that that depicts a visible goat face in ocean foam that was found not too far from this guy's sighting.
I asked him if it were okay to mention his usertag on ths wiki but he told me he "wants his privacy". So I'm going to respect his wishes.