"Many hundreds and thousands of demons, demi-demons, Yaksas, Raksasas [man-eaters] and others, headed by Sumali and Mali, resisted the armies of King Indra, which even death personified cannot easily overcome. Among the demons were Namuci, Sambara, Anarva, Dvimurdha, Rsabha, Asura, Hayagriva, Sankusira, Vipracitti, Ayomukha, Puloma, Vrsaparva, Praheti, Heti and Utkala. Roaring tumultuously and fearlessly like lions, these invincible demons, all dressed in golden ornaments, gave pain to the demigods with weapons like clubs, bludgeons, arrows, barbed darts, mallets and lances."
"Both the demigods and the demons are expert in activities involving the material energy, but the demigods are devotees of the Lord, whereas the demons are just the opposite. The demigods and demons churned the ocean of milk to get nectar from it, but the demons, not being devotees of the Lord, could derive no profit. After feeding nectar to the demigods, Lord Visnu returned to His abode on the back of Garuda, but the demons, being most aggrieved, again declared war against the demigods. Bali Maharaja, the son of Virocana, became the commander in chief of the demons. In the beginning of the battle, the demigods prepared to defeat the demons. Indra, King of heaven, fought with Bali, and other demigods, like Vayu, Agni and Varuna, fought against other leaders of the demons. In this fight the demons were defeated, and to save themselves from death they began to manifest many illusions through material maneuvers, killing many soldiers on the side of the demigods. The demigods, finding no other recourse, surrendered again to the Supreme Personality of Godhead, Visnu, who then appeared and counteracted all the illusions presented by the jugglery of the demons. Heroes among the demons such as Kalanemi, Mali, Sumali and Malyavan fought the Supreme Personality of Godhead and were all killed by the Lord. The demigods were thus freed from all dangers."
Srimad-Bhagavatam 8:10 Summary
"Having been graced by the Supreme Personality of Godhead, the demigods began fighting the demons again, with renewed energy. King Indra released his thunderbolt against Bali, and when Bali fell, his friend Jambhasura attacked Indra, who then cut off Jambhasura's head with his thunderbolt. When Narada Muni learned that Jambhasura had been killed, he informed Jambhasura's relatives Namuci, Bala and Paka, who then went to the battlefield and attacked the demigods. Indra, King of heaven, severed the heads of Bala and Paka and released the weapon known as kulisa, the thunderbolt, against Namuci's shoulder. The thunderbolt, however, returned unsuccessful, and thus Indra became morose. At that time, an unseen voice came from the sky. The voice declared, "A dry or wet weapon cannot kill Namuci." Hearing this voice, Indra began to think of how Namuci could be killed. He then thought of foam, which is neither moist nor dry. Using a weapon of foam, he was able to kill Namuci. Thus Indra and the other demigods killed many demons. Then, at the request of Lord Brahma, Narada went to the demigods and forbade them to kill the demons any longer. All the demigods then returned to their abodes. Following the instructions of Narada, whatever demons remained alive on the battlefield took Bali Maharaja to Asta Mountain. There, by the touch of Sukracarya's hand, Bali Maharaja regained his senses and consciousness, and those demons whose heads and bodies had not been completely lost were brought back to life by the mystic power of Sukracarya."
Srimad-Bhagavatam 8:11 Summary
Bhaktivedanta Book Trust. Excerpted from texts and purports of HDG A.C. Bhaktivedanta Swami Srila Prabhupada.