A low caste tribal boy, he practised archery for years keeping the statue of Guru Dronacharya who only taught the royal family before him. Realising that the boy was a better archer than Arjun, his favourite and known to be the best student, Guru Dronacharya asked him to cut of his thumb as 'guru dakshina' (a tradition in which a disciple gives an offering to his master for the learning he has achieved). Who was this young boy?