Aghasura (अघासुर), is a demon (asura) in Hindu and Vedic mythology.
He was one of the generals of King Kamsa.[1][2]
'A study of the Bhagavata Purana; or, Esoteric Hinduism' by Purnendu Narayana Sinha, p. 247 mentions Agha as one of the tribes in alliance with Kamsa. Kamsa With the alliance of the Magadhas ( people of Magadha or ancient Bihar) and with the help of Pralamba, Baka, Chanura, Tri-navarta, Agha (अघा), Mushtika, Arishta, Dvivid, Putana, Kesi, Dhenuka, Vana, Bhouma and other Asuras, tormented the Yadavas. They fled away to the kingdoms of Kuru, Panchala, Kekaya, Salva, Vidarbha, Nishadha, Videha, and Kausala. Some only remained behind and they followed the behests of kamsa. [3]
The Bhagavata Purana states that he assumed the form of a vast serpent.[4] Krishna's companions, the cowherd boys, entered its mouth, mistaking it for a mountain cavern. After seeing this, Krishna then came to their rescue, killing Aghasura.
Killing of Aghasura by Lord Krishna is narrated by sage Sukadev to king Prakshit in Srimad bhagavatam. King Kamsa had made many attempts to kill Krishna. All his attempt was failed. Then he sent Aghasura to kill Krishna .Aghasura is the younger brother of Putana and Bakasura. As Putana and Bakasura were killed by Krishna, Aghasura decided to kill Krishna and cowherd boys . He assumed the form of huge python of 8 mile long and he opened his mouth which look like a cave of a mountain. All the cowherd boys entered the mouth of the demon mistaking it to be a cave. Krishna also entered in to his mouth.
Krsna had increased the size of His body, the demon extended his own body to a very large size. Nonetheless, his breathing stopped, he suffocated, and his eyes rolled here and there and popped out. The demon's life air, however, could not pass through any outlet, and therefore it finally burst out through a hole in the top of the demon's head. Thus Kirsna killed Aghasura