This paper examines the identity of the deity associated with the periodic destruction of the cosmos as found in the numerous pralaya upamāna in the Mahābhārata. While this deity is usually identified as Siva in the Purānas and later texts, the present paper contends that the situation is rather different in the Mahābhārata, and probably points to an earlier stage in the myth's development. In order to establish this, the instances and characteristics of the various identifications given in these similes are considered in some detail. Antaka, Kala, Krtānta, Kalantaka, Rudra/Siva and Yama are each examined in separate sections. From this examination, the conclusion is drawn that the deity most readily identified with the role of cosmic destroyer in the Mahābhārata is Yama, either by name or, more often, by epithets associated with him. Some possible reasons for this are considered briefly, as well as the implications which this identification could have for our understanding of the myth.