Initially, a sugared concoction comprising beer, wine, and rum that was heated by inserting a red-hot poker into it. The contemporary version of a flip is usually served cold, although both age-old and contemporary recipes often include well-whisked eggs.
The drink you are referring to is called “eggnog”. Eggnog is a traditional beverage that is typically made with beaten eggs and milk, as well as some type of alcohol such as wine, spirits, or beer. Sugar is added to sweeten the mixture, and it is often flavored with vanilla, nutmeg, or other spices. Eggnog is a popular holiday drink in many countries, particularly in North America and Europe, and is often served cold and garnished with whipped cream or a sprinkle of cinnamon. While traditional eggnog contains alcohol, non-alcoholic versions are also available for those who prefer not to consume alcohol.