A popular Canadian cocktail that originated in 1969 in Calgary, Alberta, Canada. A caesar comprises of 1 ounce vodka, 4 ounces tomato-clam juice (typically Motts Clamato juice), and a dash of Worcestershire sauce with several splashes of horseradish. Most times, the caesar also comes with a stick of celery and sometimes a twist of lime.

Complete details can be found at: http://hotwired.lycos.com/cocktail/96/40/index4a.html

This drink is apparantly impossible to get in most parts of the US, since no one seems to carry Clamato juice. I know this is the case for sure in Sacramento, since no bartender I talked to there had ever heard of a Caesar.