Pulque
Pulque is a milky, mildly alcoholic drink made by fermenting aguamiel, the sweet sap extracted from the heart of the maguey (agave). It has been drunk since pre-Hispanic times, when it was considered sacred and its consumption was strictly regulated.
Don’t confuse it with tequila and mezcal, which also come from agave plants but are distilled spirits, not fermented sap.