This paper investigates the cognitive mechanisms underlying eating and drinking metaphors in Mongolian and discusses complex linguistic features of some culturally unique idioms relating to id- ‘eat’ and uu- ‘drink’, which are interpreted from a sociocultural perspective, along with the help of world knowledge. Metaphorical extensions of id- and uu- fall into three subcategories: (1) agent-oriented extensions, highlighting the consumer’s role in the source domain of eating and drinking; (2) patient-oriented extensions, focusing on destructive effects on the patient in the source domain; (3) extensions involving both agent and patient orientations, describing the agent’s sensation and “destruction” of the patient at the same time. Based on the Mongolian Web Corpus (mnWac16) and an extensive online dictionary (mongoltoli.mn), it is found that patient-oriented extensions tend to be more connected with EAT verbs in Mongolian, denoting a range of extensions like overcoming of the patient, spending material wealth, psychological torment or destruction, corrosion caused by external factors, etc., while agent-oriented extensions are more likely to involve DRINK verbs, denoting ‘smoking’, receiving material wealth (e.g., earning money) and absorption of such liquids as ink or oil. Overall, id- has a broader extension than uu-, and there are some overlaps involving both agent and patient orientations in terms of living on material wealth and physical exploitation. Some common usages pertaining to metaphorical extensions of consumption verbs are found cross-linguistically.