This is such a tasty, refreshing drink--in all of its forms, I thought: "Why not expound on it". The "Mule" is a 'sub-category' of long drinks called 'Highball's, that is made with ginger beer, a squeeze of lime and a spirit of your choice. Since this is Mezcal Monday, I choose Mezcal! The name is self explanatory... Mezcal comes -primarily- from Oaxaca, and thus the name. To me it conjure lovely images of mules hauling wood / agave to the palenque to begin the process of making this wonderful spirit.