Swampy (aka Swamp Donkey) is known chiefly by his horned skull, conjuring up the idea of an elephant with the two long tusks curling down, as well as two smaller horns protruding from the area where the ears would be. Swampy's character very often also has an upside down cross on it's forehead.
The identity of Swampy is kept secret but he did at one time have a website which talked about his life of riding freights across 49 of the state in the US. The only state not included is Hawaii due to it's lack of an accessible rail system. He is said to know all the tricks to riding the freights which is a fabled sub-culture of it's own tracing back deep into hobo lore. To successfully ride the freights is a dangerous proposition requiring the need to evade the police, train crew, and avoid getting rolled on.
In addition to riding the freights is said to squat in empty buildings once he arrives in town, and stays there until the police or owners kick him out. He recently had an exhibit in the Bay Area called "In My Room" in which he lived inside a room in an art gallery for several days which could only be accessed by a trap door. The exhibit brings to mind the dual role facing many Street Artists as their work becomes marketable by the established art community as well as the need to stay current on the streets to maintain credibility in the highly opinionated Street Art community.
Swampy took down his website because as the story goes he didn't want to keep promoting a dangerous lifestyle where people could get seriously injured or even die in the unforgiving world of renegade freight travel. According to a tumblr log set up by a hardcore fan he did this after hearing about a girl that got badly injured on the freights after becoming interested in the adventure after coming across his website. There is also a coffee table style book that he released which features a lot of his photos and writing revolving around his experiences traveling across the country.
If you have any additional information about Swampy I would love to hear it!