William Millyon, aka "Willie the Fifth", was an underworld figure who operated in Dick Tracy's city. He operated the criminal activity in the city that previously been overseen by Mr. Crime and Odds Zonn. Millyon owned a bar which included living quarters in the basement and a secret room from which Fifth conducted his criminal business. He was a physically imposing man who often smoked cigars. He typically wore a wide-brimmed fedora which covered his eyes, and a necktie with a number 5 on it.