Jim Kaplan is a conman, characterized by his permanent wide insincere smile. He has a bank, and tattoo parlor. Many of his cons are directed at Peter since he is so gullible and easy to fool. He was also once a sports agent, willing to give his clients anything he owns to get them to sign a contract. He sold Peter volcano insurance, but when Lois discovers what he has done, she sends Peter to get the money back. He also sold Peter a tank, when he took Meg out to buy a car (who, of course, rarely got to drive it).
This guy is also known as; "The Salesman" and he was once called himself "Doug". Danny Smith, the salesman's creator and voice actor, explained in a DVD commentary that the character's name is not really Jim Kaplan, but an alias he used in his business dealings.