I can't believe nobody has mentioned Anthony Casso.

Casso realized early on that killing other made guys and taking over their rackets was very lucrative. Granted, these hits were ordered by higher ups, but when Casso was put in more powerful positions I believe he continued this practice of killing other guys to take over their rackets. Casso admitted to 33 murders, only 4 or 5 US serial killers have committed more murders than that. There was no sense of brotherhood or "family" when it came to Casso. Other made men were simply there to be exploited by him.

Other transgressions include killing made guys for no good reason other than greed and paranoia, like the hit on Michael Salerno. He did nothing wrong, but Amuso and Casso felt he was getting too powerful so they labelled him a rat and ordered his death.

Then of course Casso turned informant and threw everyone he knew under the bus.

A true piece of shit.