Of all the killers in Bugsy Siegel's infamous Murder Incorporated, the employee of the year honors pretty routinely went to Harry Strauss. Known as "Pep" to his friends, Strauss would typically celebrate a night's successful kill with a lobster dinner and the company of his fellow murderers. Strauss was known for never carrying a weapon, lest he be stopped by police. Instead, he would show up at the contract scene and use whatever was on hand. Guns, bats, lumber, ice picks, screwdrivers, rope, garrote wire, bricks, extension cords, fire, tall buildings - if it could kill somebody, Strauss would find a way to use it.
He's known to be responsible for at least 100 murders in his time working for Murder Inc., but some historians speculate that he could have killed as many as 500 people. That's more than a third of all the murders committed by Murder Inc. Bugsy might have been in charge, but Strauss was almost certainly the single most prolific killer of the Prohibition era.