A cigar smoking gangster in the Spangled Mob in Las Vegas, Nevada, where he worked as a front man for the casinos they owned. Strap emerged as the gang's new leader in the aftermath of the smuggling pipeline of the Spang brothers destruction at the hand of James Bond. He took over the positions of the Spang brothers and moved the gang's interests away from diamond smuggling.
In June 1957, he was summoned to New York City by the treasurer of SMERSH, Auric Goldfinger to a meeting of other American gang leaders. After hearing Goldfinger's plan to raid the U.S. gold bullion depository at Fort Knox, he agreed to partake in Operation Grand Slam. Strap sent several of his best men from the mob to assist. The plan was to gain access to Fort Knox by disguising themselves as Red Cross employees (after Goldfinger put knockout drops in the nearby reservoir to give the appearance of a plague). Pussy Galore and her female gang would be disguised as nurses, while the men of the other gangs would be disguised as doctors. To give the image of authority over their "doctors", Strap, along with fellow gang leaders Jed Midnight, Billy Ring and Mr. Solo, wore medical robes with the insignia of senior physicians.
After the raid failed due to James Bond's message to Felix Leiter, Goldfinger personally executed Strap by gunshot, along with other mob bosses he hired for the job.
Jack Strap is described as being about 50 years old with frightening, cruel eyes like a quick conjuror. He wears an expensive suit of shiny material and smokes a cigar.