The owner of a tobacco shop in Ankh-Morpork, Bewilderforce Gumption is one of many shopkeepers in the city who have, for better or worse, made the acquaintance of Fred Colon. As a result, the suggestion that a policeman might actually pay for any of his products is completely alien to him.
While he would claim to anyone who asked that the Patrician's tax on tobacco has been having a terrible impact on his business, in fact (thanks to connections with smugglers), his business has been booming. He'd been dressing better and buying tickets to the opera, perhaps at his wife's insistence that they be upwardly mobile into higher society. Even Nobby Nobbs noticed that he was in the process of reducing his prices, and taking on new staff.
Fred Colon buys a cigar from him in Snuff that turns out to contain a goblin Unggue pot. After analysis from the Watch's forensics department confirms it as a "soul of tears" pot (that is, a pot belonging to a goblin mother who had to eat a child), it takes him over, leaving him helplessly ill and thinking he is a goblin. Cheery Littlebottom and Wee Mad Arthur visit Bewilderforce to investigate, and find out, after a simple threat to send A.E. Pessimal round to have a look in his paperwork, that the cigar in question came from plantations in Howondaland owned by Gravid Rust.