A very strange, confused, socially retarded (possibly mentally retarded) person who has nothing better to do apart from to wander aimlessly around the town centre all day making everybody who comes into contact with them feel slightly worried.
Not to be confused with a tramp/hobo, town moochers usually are fairly clean and probably have a small flat somewhere possibly even a job and/or a fellow town mooching partener/family.
Oh my days! Here comes that family of town moochers, why does the mum always wear a crash helmet?"
"Hey mate, if you don't stop hanging around town every day, people gonna start calling you a town mooch"