Creator: James Cagney

"You dirty rat!"
Not James Cagney note 

James Francis Cagney was an American film actor most famous for gangster roles in the 1930s and 40s, as well as for his alleged catchphrase. He starred in some of the best gangster pictures ever made, including Angels with Dirty Faces, White Heat, The Roaring Twenties, and The Public Enemy, which is unfortunately mostly remembered for a scene in which he shoves a bowl of grapefruit in a woman's face.

What isn't commonly known is that Cagney began his career as a song & dance man. Even after he was type cast as thugs, he leaped at chances to act and dance in musicals whenever he could.

His tough guy persona wasn't all for show, though; Cagney staggered Warner Bros. by walking off the lot when the studio failed to honor his contract. His example set a precedent for fairer studio practices. On the other hand, Cagney's activism landed him hot water; he was branded a Commie in some circles. His iconic role in Yankee Doodle Dandy dispelled such rumors pretty quick.

Michael J. Fox is one of his biggest fanboys, for obvious reasons. He hosted a TV special on Cagney's life and times entitled Top of the World.

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