Who is Old Ike from Junky and what is their importance?

Old Ike is a junky who lives in Mexico City. Bill describes him as a shabby, middle-aged man with a toothless mouth and withered brown skin. Old Ike has used drugs for twenty-eight years at the time he makes Bill's acquaintance. He supports himself by selling religious medals or objects made from fake silver. Ole Ike supplies Bill with drugs until Bill develops a strong habit. Then Old Ike gets a legal medical dispensation to purchase morphine in bulk; Bill supplies the funds and the two men split the medical morphine supply for personal use. Eventually Bill stops using drugs and Old Ike drifts away, continuing as an addict. Late in the novel Old Ike appears again and gives Bill an occasional injection. Of all the characters presented in the novel, Old Ike is the most developed—still only marginally more than a vignette—and also one of the most unique.