Ilvala was a Daitya (demon) of deceitful nature. In Bhāgavatapurāṇa (Bhagavatapurana), there is a detailed description of his genealogy. Hlāda (Hlada) was the son of Hiraṇyakaśipu (Hiranyakasipu). Ilvala and his brother Vātāpi, sired by Hlāda were born of the womb of Dhamanī (Dhamani). So according to the description of Bhāgavatapurṇa, Ilvala was the grandson of Hiraṇyakaśipu. As per other Purāṇa(s)(Purana; Mythological Scriptures), Ilvala was the nephew of Hiraṇyakaśipu. Vipracitti, a king of Danava, got married to Hiraṇyakaśipu’s sister Siṁhikā. Ilvala was one of the demons born of the womb of Siṁhikā (Simhika), sired by Vipracitti (Viprachitti). We get the mention of Ilvala among the followers of such Asura-kings as Vṛtra and Vali. Ilvala as a king of demons was famous for his immense wealth. In Mahābhārata(Mahabharata) it is mentioned that he lived in the city of Maṇimatī (Manimati). Once Ilvala asked an ascetic Brāhmaṇa (Brahmana) for a boon of a son as powerful as Indra. But the sage refused him. So Ilvala became angry with the entire Brāhmaṇa community , and started killing Brāhmaṇa(s), with the help of his black magic. Ilvala used to turn his younger brother Vātāpi into a goat or lamb. Then, he cut him and cook the meet to feed an invited Brāhmaṇa. Ilvala had a special power, if he called any dead person by his name, he would return to life. After feeding the Brāhmaṇa with the flesh of Vātāpi, Ilvala would call him, and Vātāpi came alive, shattering the Brāhmaṇa’s stomach. Thus Ilvala caused many Brāhmaṇa’s death
Once Sage Agastya, accompanied by some kings, came to Ilvala and asked for wealth. Ilvalla cooked the meat of Vātāpi in the form of a lamb and served them. Agastya consumed the entire food alone. When Ilvala started called Vātāpi by his name, Agastya said — “How will he come out? I have digested him.” Hearing this, Ilvala fell into misery, and gave more wealth to the sage and the kings, than they demanded. In Rāmāyaṇa, however, it is said that after learning the news of Vātāpi’s death, Ilvala became furious and attacked Agastya. Sage Agastya used his ascetic power, and burned him to ashes. According to Purāṇa, Ilvala had a son called Valvala.