Mr Hong
Mr Hong never appears in any of the books, having (apparently) died before the start of any of the stories, but appears to form an important part of Ankh-Morpork's collective memory. In several Discworld books, a character is admonished to "remember what happened to Mr Hong when he tried to open the Three Jolly Luck Takeaway Fish Bar on the site of the old fish god temple in Dagon Street on the night of the full moon." This incident appears to act as a deterrent for Morporkians against meddling with the occult or supernatural or doing something that is patently stupid. Though it is never satisfactorily explained exactly what happened, in Jingo it is revealed that only his kidney and a few bones were found; in the game Discworld Noir his shop was used as a location for one of the murders. Found boarded up, deep investigation reveals that a local thespian from the Dysk theatre was eaten there.
Read more about this topic: Discworld Characters