While I have yet to find an American traditional pigman, I have found one on the Isle of Man. The Isle of Man is a small British dependency in the Irish Sea, ruled by, but not part of, the United Kingdom. The adjective relating to it is Manx. The Manx cat, for example, is a breed noted for lacking a tail.
|Flag of Isle of Man|
The Manx have a legend about a creature called Johnny Squarefoot. He started off as a large pig, the steed of a demon. After the demon had abandoned him, he was changed by magic into a man with a pig's head. This pig's head boasted a set of tusks. The creature hung out around the district of Greasby. Although fearsome of aspect, however, he does not seem to have been aggressive. What lies behind this legend? Who can say?