Ashwatthama, also called Drauni, the only son of Dronacharya was born after many years of severe penance to Lord Shiva. Ashvatthama was born with a mani on his forehead which made him fearless against any weapon, gods, devtas and nagas. The mani also made him invulnerable to diseases and hunger. Ashwatthama took his education along with Kauravas and Pandavas.
He showed quiet a valor in the battle of Mahabharat by killing son of Ghatotkacha and a battalion of rakshas. But the main turning point came after his father was killed deceptively by Pandavas which angered him and he invoked narayanastra(shower of a million missiles on enemy) on Pandav army. After Duryodhan was killed by Bhim by striking him on his thighs (this being against mace fighting laws, Balram got very angry and cursed that mace fighting be forgotten forever) he vowed to avenge Duryodhan's death by killing all Pandavas.
Ashwatthama observed how an owl was attacked by crows in the day and how the owls attacked back in the night, so he with the help of Kritavarma and Kripacharya attacked the camp of Pandavs at night, killing many warriors and five sons of Panchali. Before the attack he worshiped lord Shiv and offered his body as offering in return of a boon that "whoever faces him this night shall die". Furious with what had happened in night, Pandavas with Krishna went to sage Vyas's hermitage where Ashwatthama was residing. On seeing Pandavas approaching, Ashwatthama invoked Brahmashira on Pandavas, to counter this Arjun to invoked the same weapon to nullify it, but on sage Vyas's advice Arjun took back the attack (two brahmashira would have destroyed the mortal world) but Ashwatthama unable to do so directed it to Abhimanyu's wife's(Uttara) womb, killing unborn son and only heir of the Pandavas. Seeing this Krishna got very furious and cursed Ashwatthama that he'll roam on earth alone till the end of kalyug infected with leprosy. He even snatched the mani from his forehead which gave him unique powers.
Although not many are aware of this but Pallavs (Southern kingdom near Tamil Nadu) were descendants of Ashwatthama. It is beleived that Ashwatthama married a Naga princess and had a son who started the Pallav kingdom, gotr of Pallav kings is mentioned as Bhardwaj in many texts (Bhardwaj was Grandfather of Ashwatthama).
It is fascinating to know that there have been many sighting of a large man with wound on his forehead in Gir forests of Gujarat. Many people have claimed that they have seen a huge man with leprosy like disease coming to Lord Shiva temple in Asirgarh. There is a doctor in Madhya Pradesh who swears that he has operated on Ashwatthama's forehead wound. Well who knows what is dwelling in those dense Gir forests of Gujarat....
