Goatfin was once an average Mincraftian. He adventured, he mined, he crafted. Until one day, he decided that what he had done wasn't enough. So he built himself a city. Skyscrapers, supermarkets, you get the idea. Now he builds 24/7. One time he even built a complex Restone time machine. He actually became so obsessed with building, his present whereabouts are unknown...
Since he has built a time machine, his disappearence could be related to that.
The arrow on his shirt could possibly symbolize something, like "Build from the ground up."
Reported sightings of goatfin are very obscure.
He was once said to have been seen by a minigame portal on a Bukkit server.
He was once said to have been seen near a player's house, but was gone in the next split second...
There are many more reported sightings.
Goatfin has a curl in his hair.
Though it has been said he has a city, it has never been found.