Charlie (The Truth)
Charlie was a fairly unsuccessful haberdasher in Pseudopolis when Mr. Pin found him. He wasn't successful because he was usually drunk and always a bit dim, but he had one valuable talent: he looked exactly like the Patrician of Ankh-Morpork. Mr Pin said he would pay a suspiciously large amount to have him do that for a few days.
The plot was not to substitute him for the Patrician; no, not Charlie. Not nearly reliable enough, would be Charlie. He was merely to appear to be the Patrician committing a crime, after which Tuttle Scrope could be elected Patrician and Charlie would be dispensible.
He was lucky enough not to be killed by Mr. Tulip or Lord de Worde's thugs and now does quite well as a children's entertainer, with occasional command performances when His Lordship wishes to be somewhere else.