Kartavirya Arjuna (Sanskrit: Kārtavīrya Arjuna), was a legendary king of an ancient Haihayas kingdom (Kalchuri Rajputs) with capital at Mahishamati which is on the banks of Narmada River in the current state of Madhya Pradesh. Kartavirya was son of Kritavirya, king of the Haihayas. This is his patronymic, by which he is best known; his real name was Kartaviryarjuna. He is described as having a thousand hands and a great devotee of god Dattatreya.
Vayu Purana extolls his virtues
Having worshipped a portion of the divine being called Dattatreya, sprung from the race of Atri, he sought and obtained these boons: a thousand arms and a golden chariot that went wheresoever he willed it to go; the power of restraining wrong by justice; the conquest of the earth and the disposition to rule it righteously; invincibility by enemies, and death at the hands of a man who was more powerful than himself. By him this earth was perfectly governed," and of him it is said:-"No other king shall ever equal Kartavirya in regard to sacrifices, liberality, austerities, courtesy, and self-restraint." "Thus he ruled for 85,000 years with unbroken health, prosperity, strength, and valour.
The Mahabharata mentions him as one of the best warriors and introduces his divine origin, attributing it to the Padmini Ekadasi :
The king (Kartavirya Arjuna's father) was very happy to hear this. Naturally he asked for the son he had desired for so long: 'O master of the universe, O killer of the Madhu demon, kindly grant me a son who will never be conquered by demigods, human beings, snakes, demons, or hobgoblins, but whom only You can defeat.' The Supreme Lord immediately replied, 'So be it!' and disappeared.
The king became very pleased with his wife and returned to his palace in her company. Padmini soon became pregnant, and the many armed Kartaviryarjuna appeared as her son. He was the mightiest person in all the three worlds, and thus even tenheaded Ravana could not defeat him in battle. Except for Lord Narayana, who holds a club, a disc, and other symbols in his hands, no one could overcome him. By the merit that resulted from his mother's strict and faithful observance of Padmini Ekadasi, he could defeat even the dreaded Ravana. This is not at all surprising, O Naradaji, for Kartaviryarjuna was the fulfillment of the benediction of the Supreme Personality of Godhead." With these words, Pulastya Muni departed.
The Supreme Lord, Sri Krisna, concluded, 'O sinless Yudhisthira, as you have inquired from me, I have explained to you the power of this special Ekadasi. O best of kings, whoever observes this fast will surely attain to My personal abode. And similarly, if you want all your desires fulfilled, you should do likewise.
The prayer for return of lost or misplaced things is addressed to Karthviryarjuna.