Film: Casino

Played by: Joe Pesci

The character of Nicky Santoro was based on real-life mobster Anthony 'The Ant' Spilotro. In the film Santoro is sent to Las Vegas by the bosses to make sure that the wiseguys there are kept in line. Santoro is a loose cannon in every sense of the word. In one savage scene, he stabs a man in the neck with a pen multiple times solely for insulting his friend. Yikes!