In the Mahabharatha, Ekalavya is introduced as a young prince of the Nishada tribes. Ekalavya was born to Devashrava (brother of Vasudeva, who was father of Krishna) and was raised by Hiranyadhanus, the leader (King) of the Nishadhas, who was a commander in the army of Jarasandha (the king of Magadha).
Eklavya was a small bright boy who lived near the ashrama of Drona, where Pandavas and Kauravas used to take lessons in various arts. He had great desire to learn the art of archery from Dronacharya. But his mother had told him that Drona would not accept Eklavya as his disciple. It was futile to dream of such a privilege. But the boy was not be put off, his determination knew no bounds.
Ekalavya goes off into the forest where he fashions a clay statue of Drona. Worshipping the statue as his preceptor, he begins a disciplined program of self-study. As a result, Ekalavya becomes an archer of exceptional prowess, comparable to even to Drona's best pupil, Arjuna. One day while Ekalavya is practicing, he hears a dog barking. Before the dog can shut up or get out of the way, Ekalavya fires seven arrows in rapid succession to fill the dog's mouth without injuring it. The Pandava princes come upon the "stuffed" dog, and wonder who could have pulled off such a feat of archery. Searching the forest, they find a dark-skinned man dressed all in black, his body besmeared with filth and his hair in matted locks. It is Ekalavya, who introduces himself to them as a pupil of Drona.
Arjuna feared that Ekalavya had eclipsed him in skill with the bow. Arjuna complained to his teacher Drona, reminding Drona of his promise that he would make Arjuna his best pupil. Drona acknowledged Arjuna's claim, and went with the princes to seek out Ekalavya. He found Ekalavya diligently practicing archery, as always. Seeing Drona, Ekalavya prostrated himself and clasped the teacher's hands, awaiting his order. Drona asked Ekalavya for his Gurudakshina, the deed of gratitude a student owed his teacher upon the completion of his training. Ekalavya replied that there was nothing he would not give his teacher. Drona asked for Ekalavya's right thumb, knowing that it's loss would destroy Ekalavya's mastery of archery. It is said that the trees and air around stood still for a minute. Even Arjuna was stunned upon listening to the macabre demand of his Guru. To ask for the thumb of an archer was to kill him, inasmuch as it was to divest him of his skill in archery. Ekalavya, however, gratefully and without hesitation severed his right thumb and handed it to Drona. Upon seeing the look of horror and disbelief on the faces of Drona, Arjuna and all the other Kuru princes, the young tribal prince was surprised and stated rather nonchalantly that it was indeed a small gift that his Guru had demanded and he would have happily placed his head at Drona's feet and beheaded himself, had his guru simply asked.
Drona is criticized by others over this incident. Drona was, as the epic says, protecting the fated superiority of Arjuna. Drona's love for Arjuna was more than the love he had for his own son, Ashwatthama. All this, however, does leave open the question whether Drona was justified in demanding of Ekalavya a tribute that was neither, strictly speaking, his due nor, even loosely speaking, honestly intended. The Mahābhārata does not answer this question. The story leaves room for interpretation and moral speculation. As a result, a variety of answers have been proposed to the question.