Vajrabhairava 

A tantric tutelary deity (yi-dam), thought to be the wrathful aspect of Mañjughoṣa or Yamāntaka. Meditational practices and rituals associated with Vajrabhairava are expounded in the Vajrabhairava Tantra and related texts introduced from Oḍḍiyāna by Lalitavajra. Vajrabhairava is especially venerated in the Geluk school, both in Tibet and Mongolia.

A Dictionary of Buddhism, Oxford University Press, 2003, 2004 (which is available in electronic version from answer.com)