The main ingredient in a traditional eggnog drink is egg, specifically egg yolks. Eggnog is a rich, creamy beverage often enjoyed during the holiday season, particularly Christmas. The drink is typically made by combining eggs with milk, cream, sugar, and flavorings such as vanilla or nutmeg. Alcohol, such as rum, whiskey, or brandy, is often added for an extra kick. Historically, eggnog has roots in medieval European beverages, and its preparation can vary between regions and households, but the use of eggs remains a defining characteristic of this festive concoction.