Berkeley has long hair, a light beard, a mustache, and thick eyebrows, all black. He wears vaguely rastafarian attire and sports a guitar and marijuana on hand.
Berkeley is a staunch pacifist even in the face of the undead hordes that he grew up around, and has a mellow demeanor generally. Much of his persona is faux however, such as his asserted passion for writing music. In actuality, he steals from artists such as Bob Dylan and Lynyrd Skynyrd and passes off their songs Like a Rolling Stone and Free Bird respectively, as his own creations, relying on the ignorance of his peers to hide the plagiarism.
First found hitchhiking, Little Rock and Wichita nearly ran Berkeley over with their car, standing right in the middle of the road and not moving even as the car approached him. He joined them, and told them about a new, stronger zombie that was cropping up around the country. He also told of his intentions to go to Babylon, a pacifist commune to the west. Wichita objected, so he and Little Rock stole her car and abandoned her. En route, Berkeley continued to woo Little Rock with plagiarized songs and marijuana, eventually ditching the car at Nevada's motel for being "too establishment" before continuing on.
When they arrived, the Babylon guard insisted they melt down their guns before entering, which Berkeley convinced Little Rock into agreeing with. Berkeley then remained in the commune with Little Rock until Tallahassee, Wichita, and Columbus arrived. A zombie attack occurred shortly afterward, so Berkeley helped to defend the commune by dropping items from the top of the Babylon tower onto approaching zombies, as well as by helping to reinforce the funnel to channel the horde to the edge of the tower and to their deaths.
After defeating the zombies, Little Rock broke up with Berkeley, citing his plagiarism, and left with her makeshift family. Berkeley stayed in Babylon with Madison.