Śiva is a deity of the Hindu Trinity and is responsible for the laya or pralaya, dissolution, of the universe. One of the names, by which he is well-known, is Pañcānana or Pañcamukha, ‘the five faced one’. These five faces are actually five aspects of his manifestation. ‘Aghora’ is one of these five. Facing south and ruling over the element agni (fire), Aghora stands for the power that absorbs and renovates the universe.
Iconographically, he is shown with a terrific face and eight hands holding śūla (spear), ḍamaru (drum), pāśa (noose), kapāla (skull-cup), daṇḍa (staff), cāpa (bow), bāṇa (arrow) and asi (sword). The neck is blue and the rest of the body is black. The body is either naked or clad in the hides of elephant and lion. Snakes and scorpions form the ornaments.
Since his terrible form frightens away all the sufferings of his devotees, who have taken refuge in him, he is ‘Aghora,’ the ‘not terrible’ to them.
The mantra beginning with the words ‘aghorebhyo’ in the Mahānārāyaṇa Upaniṣad (19.1) is known as ‘aghora-mantra’ and is one of the five mantras well-known as ‘pañcabrahma-mantras’ employed in the worship and meditation of Mahādeva Śiva visualised as having five faces.
These mantras are normally prescribed for japa to a person who desires divine illumination.