Tosher should not be confused with Tosser.
A tosher is someone who scavenges in the sewers, a sewer-hunter, especially in London during the Victorian era. The word tosher was also used to describe the thieves who stripped valuable copper from the hulls of ships moored along the Thames. The related slang term "tosh" referred to valuables thus collected. Both "tosher" and "tosh" are of unknown origin.[1]
A tosher in Victorian London is the profession of the title character in Dodger, a 2012 novel by Terry Pratchett.[2]
The protagonist of Nick Harkaway’s 2012 novel Angelmaker describes the London sewers and backstreets as “Tosher’s Beat”.
The character Murky John is a Tosher in Year of the Rabbit Series 1 Episode 2.