He was a homeless Irishman living in New York city in the 1920s. He was most famous because 5 acquaintances tried to murder him to collect on life insurance policies that they took out on him.
Three of the 5 got policies on Malloy, which came up to be over $3500 (in 2011 dollars, over $60,000). This set off the plot to kill him. One of the conspirators owned a bar, and gave Malloy unlimited credit, thinking that he would drown himself to death in alcohol. When he did not die in alcoholism, they mixed in antifreeze instead of liquor. Malloy still lived. Then, they substituted it with turpentine, horse liniment and even, rat poison. He still lived.
They tried feeding him raw oysters soaked in methanol, and then a sandwich of spoiled sardines mixed with poison and carpet tacks. Their attempts got more and more ridiculous! They eventually decided to see if they could freeze him to death.
On a night that reached -14F, Malloy blacked out drinking. The murderers carried him to a park, poured 5 gallons of water on his bare chest and left him to die. He came back for a drink the next day. Then they hit him with a cab at 45 miles per hour. Iron Mike still lived.
They finally managed to kill him one night when they strapped him to a gas hose and turned it on. He was pronounced dead of lobar pneumonia. However, there was justice in this case. The 5 men squabbled too much on how to divide the loot and when the police heard rumors of Mike the Durable, they investigated and it led to their arrest. One went to prison, the other four were given the electric chair.