"No spectator has ever been bold enough to grapple with the back streets - the human warrens - on the south side of the metropolis..." John Hollingshead, Ragged London.
My favourite Southwark character is Springheeled Jack - but I don't think he really exists, which is probably just as well! Built on the back of more famous criminals such as Jack the Ripper, our springheeled friend was a 19th century urban legend - a shady figure, haunting the backstreets and alleyways of deserted dockland areas and rookeries, so called because of his nasty habit of pouncing on women when they least expected it. Another characteristic of his was belching flames and laughing madly in people's faces - what a rotter. He is supposed to have thrown an unfortunate prostitute to her death in Folly Ditch, part of the Dickensian slum known as Jacob's Island.