He is best known for his sacrifice in the Puranas, where he gives up his life so that his bones could be used to manufacture the Vajra, the diamond-like celestial thunderbolt of the deity Indra, in order to slay Vritra.
After the death of Dadhichi, when Suvarcas was about to ascend the funeral pyre, she heard an aśarīriṇī vāṇī (a celestial voice) that informed her that she was pregnant.
[9] In a variation of this legend featured in the Jaiminya Brahmana, the devas are said to have refused to bestow the Aśvaśira mantra of the Vedas to the Ashvini Twins.
[10] The Shiva Purana features the sage as a friend of the splendid King Kṣuva, a great devotee of Vishnu.
Angered that the king would express an opinion that was contrary to the scriptures, Dadhichi struck the head of Kṣuva with his left fist.
The sage remembered Shukra, his ancestor, and the narrator of this legend, who employed his yogic powers to restore Dadhichi's limbs, and taught him the Mahāmṛtyuñjaya mantra to propitiate Shiva.
When appeased, the deity appeared to offer the sage any boon of his choice, and Dadhichi wished for three: indestructible bones, immortality, and freedom from distress.
The sage employed a few blades of the kusha grass against the divinities, which transformed into a trishula, frightening all but Vishnu from the scene.
[18] Indra then brought all the water of the holy rivers together at Naimisharanya,[18] thereby allowing the sage to have his wish fulfilled without a further loss of time.
[19] Another version of this legend exists where Dadhichi was asked to safeguard the weapons of the devas, as they were unable to match the arcane arts being employed by the asuras to obtain them.
Dadhichi is said to have kept at the task for a very long time and, finally tiring of the job, is said to have dissolved the weapons in sacred water, which he then drank.
Realising that his bones were the only way by which the devas could defeat the asuras, he willingly gave his life in a pit of mystical flames, that he summoned with the power of his austerities.
The design of the Param Vir Chakra, an Indian military medal, is regarded to be inspired by the sacrifice of this sage.