Dan Cody was a middle-aged millionaire who gave James Gatz—later, Jay Gatsby—his first taste of the lives of the uber-wealthy. According to Gatsby, Cody had made his money through the mining of precious metals, striking it rich during the iconic Gold Rush of the late 19th century. However, Gatsby paints Cody as an alcoholic whose careless and gullible nature makes him the easy target of opportunistic leeches looking to exploit his wealth. Particularly, Cody has the habit of falling prey to women who are far more interested in his money than his romantic affections. When Gatsby first meets Cody, the millionaire’s current wife has sent him out on a long yachting expedition, while presumably enjoying the spoils of his wealth back in Boston. Cody’s relationship with Gatsby seems to be a healthier one. Gatsby becomes Cody’s professional and personal caretaker, while Cody becomes Gastby’s mentor and guide through the world of the wealthy.
However, Gatsby’s years of service to and friendship with Dan Cody are not entirely pure, as Gatsby wants something (namely wealth and reputation) from Cody. The soft-mindedness that made Cody vulnerable to the manipulations of Ella Kaye also made him vulnerable to the manipulations of Gatsby. While Gatsby may be friendlier and ultimately kinder than Ella, there is no doubt that he too is a striver who is possessed by the singular obsession of amassing wealth. His relationship with Cody is contrived from the very beginning. Although Cody doesn’t know it, Gatsby rowed out to Cody’s yacht with the intention of striking up a connection that would be advantageous to him, and used a false, affluent-sounding name to create the illusion that he was wealthier than he actually was. Cody, like many of the wealthy people in The Great Gatsby, is surrounded by people who have ulterior motives for striking up a relationship with him, to the extent that there’s an unspoken implication that his own wife may have orchestrated his death. In this sense, Gatsby follows in the footsteps of his mentor: Cody’s untimely death and lack of true friends foreshadows Gatsby’s own fate.