Near the end of the great Kurukshetra war, after Bheema had defeated Duryodhana by smashing his thighs using a mighty mace, Ashwatthama, son of Guru Drona, and one of the last remaining warriors of the Kuru army, vows to a dying Duryodhana, that he will take Duryodhana’s revenge from the Pandavas, for defeating him, his brothers, and his mighty army. Duryodhana appoints Ashwatthama as the final Commander-in-chief of the Kuru army.

Ashwatthama attacks the Pandava camp at night, which was not allowed, as per the rules of the war. Ashwatthama slaughters warriors of the Pandava army, while they were asleep, and bore no weapons, including Drishtadyumna, brother of Draupadi, and Commander-in-chief of the Pandava army, and the Upandavas, the sons of Pandavas with Draupadi. The Pandavas, who were away at night, came back to the camp, and were inconsolable, after finding what great sin Ashwatthama had committed, and realising the fact that even after winning the great war, they now remain heir-less, and have no descendants to celebrate their victory with. Ashwatthama breaks the news of his attack to a suffering Duryodhana, who after listening to the great tragedy that had befallen upon the Pandavas, now finally breathes his last, and dies.

The enraged Pandavas immediately rush out to kill the greatest sinner of them all. Ashwatthama evokes the Brahmastra, one of the most powerful, and destructive weapons, mentioned in the Mahabharata, to defeat the Pandavas, and fulfil his promise to Duryodhana. To counter the great weapon, Arjuna evokes his own Brahmastra, but Guru Vyasa intervenes, and asks them not to let the two divine weapons collide, as it would be catastrophic, and possibly wipe out everything from existence, ending creation itself. Arjuna takes back his Brahmastra. But Ashwatthama not knowing, how to take it back, fires the weapon at Uttara’s womb, instead of the Pandavas.

Uttara was carrying the only remaining, unborn descendant of the Pandavas, the child of Abhimanyu. Abhimanyu, son of Arjuna, was a great warrior, who was trapped in a ‘Chakravyu’ and slain during the war. After witnessing the great sins that Ashwatthama had committed, Lord Krishna, filled with rage, took the ‘Mani’ (the gem), which was attached to Ashwatthama’s forehead since his birth. The Mani protected Ashwatthama from illnesses, and provided him with special physique and powers. Then Lord Krishna cursed Ashwatthama with Immortalilty. He (Lord Krishna) said while cursing Ashwatthama that, you (Ashwatthama) will carry the burden of all the people’s sins on your shoulders and will roam alone like a ghost without getting any love and courtesy till the end of Kali-yuga. You will have neither any hospitality nor any accommodation. You will be in total isolation from mankind and society. Your body will suffer from a host of incurable diseases forming sores and ulcers that would never heal. May you, Ashwatthama, lead the most wretched life anyone can ever lead. May you never receive love or affection ever in your life. May you aspire for death everyday, but it'll never come to you, unto the end of Time. Lord Krishna then saved Uttara’s child with his divine powers, and named him ‘Parikshit’ (literally meaning tested), the one who was tested even before his birth. Parikshit went on to become the ruler after Yudishthira.

Till present day, sightings of Ashwatthama have been reported in areas near the Indian states of Uttar Pradesh and Madhya Pradesh. And people CLAIM to have witnessed him offering flowers to Shivalings at temples. A particular interesting account that I found online was of a Vaidya (Ayurvedic Doctor), in Madhya Pradesh. He had a tough patient with a septic forehead. After several applications of a fail-proof potion, wound was still fresh and kept bleeding. Amazed at this, the doctor wittingly said, “Your wound seems ageless and cureless. I wonder, are you Ashwathama.. hahaha”. At the third ‘ha’, he turned around to apply the next doze and found that the seat was empty. The patient just disappeared into thin air. Now, these 'claimed sightings' by people are probably false, and just hoax and rumours, who knows how much truth there is to these, but I certainly found them interesting and worth mentioning.