If the Moscow Mule wasn’t familiar to you, you may recognize the name “Dark and Stormy.” It’s often billed on cocktail menus right beside its cousin. The Dark and Stormy is actually just another simple variation on the Moscow Mule. The Dark and Stormy combines ginger beer with the equally-tropical flavor of rum. The rum adds a bit of sweetness to the cocktail and mellows out the bright flavors, opting for a darker finish. The Dark and Stormy is an excellent (and popular) tropical deviation from the Moscow Mule.