Context

This famous line is spoken by Peter Clemenza, played by Richard Castellano, in The Godfather (directed by Francis Ford Coppola, 1972). 

When the Corleone family can't get a hold of Luca Brasi, they wonder what happened to him and where he is. The answer comes almost immediately, in the form of a mysterious brown paper package (was it tied up with string?). 

Inside? Two fish wrapped in a bullet-proof vest.

No, it's not a delivery intended for the sushi restaurant next door. As Clemenza explains, "It's a Sicilian message. It means Luca Brasi sleeps with the fishes." In other words, he's been dumped in the ocean for a deep, deep sleep.

Where you've heard it

Unless you've taken a nap at an aquarium, you've probably just heard this one in connection to the movie. It's one of the most popular lines from The Godfather, and has taken on a life of its own as a mobster threat.

Additional Notable References

• The Grammarphobia blog explores the origins of the phrase.
• Of course this line has been used by mobster caricature Fat Tony on The Simpsons.

Pretentious Factor

If you were to drop this quote at a dinner party, would you get an in-unison "awww" or would everyone roll their eyes and never invite you back? Here it is, on a scale of 1-10.

Sleeps with the fishes sounds kind of cute doesn't it? Finding a bloated dead body washed up on the shore, though… not so much.