Given its name, you might think that a Bloody Mary has real blood in it, but it is simply vodka and tomato juice plus citrus, garnish, and spices. There are many variations, but you may not have heard the origin of the beverage.
Fernand Petiot is purported to have invented the Bloody Mary, either in a Paris or New York bar, during the early 1900s. It may have been named after one of his patron's girlfriends, Mary, who worked at the "Bucket of Blood" cabaret.
Despite often being cited as the creator of the Bloody Mary, Petiot later stated he "refined" a drink made by actor George Jessel, adding everything but the vodka and tomato juice. Jessel combined vodka and tomato juice to treat a hangover, and when his friend Mary spilled it on herself, the name became self-evident.