Ususama also Usushima 烏芻渋摩 is a transliteration of the Sanskrit Ucchusma, originally an epithet of Agni, the Indian god of fire, meaning one whose crackling becomes manifest. He is also known by various other names such as Eshaku Kongō 穢跡(積)金剛, Jushoku Kongō 受触金剛 and Kazu Kongō 火頭金剛. He is regarded by some as the wrathful manifestation of Fukū jōju 不空成就, one of the five Buddhas of the Diamond Realm Kongōkai gobutsu 金剛界五仏, and in the Tendai 天台 sect he replaces *Kongōyasha Myōō 金剛夜叉明王 as one of the five great Myōō *Godai Myōō 五大明王 who are the fierce gods who preside over the five directions, in which case he oversees the northern quarter.
His cult appears to have been popular in China, and paintings of him are found among the murals of Dunhuang (Jp: Tonkō 敦煌) where are preserved the cave paintings of a thousand Buddhas from the Tang dynasty. He was introduced to Japan from China by the priest *Kūkai 空海 (774-835), and he was invoked especially in rites for easy childbirth, and the removal of impurities associated with childbirth. In the Shingon 真言 and Zen sects he is also revered as the tutelary god of the toilet.
Ususama assumes a variety of wrathful forms with two, four, six or eight arms, and is often adorned with skulls and snakes, and enveloped in flames. An example of a two-armed image is preserved at Zuiryūji 瑞龍寺 in Toyama Prefecture. The texts also describe a number of mandara 曼荼羅 associated with Ususama, but there are few actual examples of them.