Once there was a young prince from the Nishadha tribe called Ekalavya who was interested to learn archery and hence he meets Dronacharya and asks him to be his guru. But, Dronacharya rejects him, saying that he is not from the kshatriya caste. So Ekalavya builds a clay model of Dronacharya and starts to practice archery and learn military arts, all by himself. He eventually becomes quite skilled, reaching the level of Arjuna.
Once when training, he comes across a dog which is barking continuously. So he fires 7 arrows in quick succession into the mouth of the dog, silencing it but not injuring the animal in the slightest. The Pandavas come across this dog and they are surprised to see such a feat of archery performed by someone other than Arjuna. As they go into the forest, they come across Ekalavya practising archery and are astounded by his skills. Arjuna gets concerned seeing this, as he is afraid that Ekalavya may surpass him in archery. He immediately reports this to Dronacharya and reminds him of his promise to not let anyone surpass the legacy of Arjuna.
Dronacharya agrees and upon going to visit Ekalavya in the forest, he gets enraged on seeing his clay model. He sees that Ekalavya has studied all by himself without the help of anyone under the watch of his image. He then asks Ekalavya to pay a gurudakshina (teacher’s fee) by cutting off his right thumb, for using his model. Ekalavya happily cuts his thumb and gives it to Dronacharya without any hesitation. This affects his ability as an archer and hence goes to show Dronacharya’s bias towards Arjuna.
Ekalavya later serves as a confidant of king Jarasandh. He even went on to become a very valiant fighter in Jarasandh’s army. He was then later killed by Lord Krishna when he tried to hurl a rock at him.