There's a reason that some non-Jews call Purim the Jewish Mardi Gras or the Jewish Halloween. The holiday, according to the Book of Esther, commemorates the salvation of the Jewish people by Esther and Mordecai in ancient Persia from the anti-Semitic official Haman. Usually celebrated in March, Purim (which literally means "lots") is typically marked by costumes, food and parades. In many cases it also involves a lot of drinking. Though interpretations differ, the Talmud is said to require people to drink until they cannot tell the difference between the evil Haman and the good Mordecai.