Kamsa and the Demons

Kamsa

Kamsa: is the brother of Devaki, and ruler of the Vrishni kingdom with its capital at Mathura. His father was King Ugrasena and mother was Queen Padmavati. However in reality, Kamsa was not the biological son of Ugrasena. In the Bhagavata Purana, it is revealed that a demon, Kala Nemi, was flying over the city of Mathura and upon viewing Padmavati's irresistible beauty, he took the form of Ugrasena and seduced Padmavati, resulting in the birth of Kamsa.

Kamsa was told in a prophecy that the eighth child of his sister Devaki would kill him, that eight child being Krishna, who Kamsa attempted to assassinate on many occasions by sending demon after demon to attack Krishna and his village. 

The Demons: 

Below we see a few examples of the many demons the Kamsa sent after the young Krishna

Putana:

Putana, the "killer of infants", was sent by Krishna's evil uncle Kamsa to kill Krishna. Putana assumed the disguise of a young, beautiful woman and came to Krishna's home-town. Her beauty resulted in her being mistaken by gopas (cowherds) as a manifestation of goddess Lakshmi. Stunned by her beauty, Krishna's foster-mother Yashoda allowed Putana to take the infant Krishna in her lap and suckle him. Putana had smeared her breast with an mandana, an intoxicant, to kill Krishna. However, Krishna squeezed her breasts and sucked her life (prana), as well as her milk. In pain, Putana screamed, pleading for her release, but in vain. She ran out of the town with Krishna still clinging to her and finally fell dead. She then assumed her real demonic form, turning trees to the distance of three gavyuti (a unit of distance equivalent totally to 12 miles) to dust. The people of Vraj cut Putana's body, burying her bones and feet and burning the flesh and skin. The fragrant smoke rose out of the flames, as Putana was cleansed of all sin by breast-feeding Krishna and she attained the same heaven that Yashoda acquired. Thus, Putana, like Yashodha, is also considered as a foster-mother of Krishna as she breast-fed him.

  

Vatsasura:

Once, when Krishna and Balarama were playing on the bank of the Yamuna, a demon of the name Vatsasura assumed the shape of a calf and came there intending to kill the brothers. By taking the shape of a calf, the demon could mingle with other calves. Krishna, however, specifically noticed this, and He immediately told Balarama about the entrance of the demon. Both brothers then followed him and sneaked up upon him. Krishna caught hold of the demon-calf by the two hind legs and tail, whipped him around very forcibly and threw him up into a tree. The demon lost his life and fell down from the top of the tree to the ground.

Bakasura:

Bakasura was the brother of Putana, whose story is given earlier. Bakasura took the form of a giant bird and terrorised the cowherds and cowherdesses of Gokul. Krishna, in an act of bravery entered the beak of the bird, and then the bird closed its beak. But Krishna wriggled round and round inside so as to make Bakasura uneasy and ultimately Bakasura had to vomit Krishna out and he died on the spot. 

Kaliya:

Once Krishna and herdboys were playing ball, and while playing Krishna climbed up the Kadamba tree and hung over the river bank, the ball fell into the river and Krishna jumped after it. Kaliya rose up with his hundred and ten hoods vomiting poison and wrapped himself around Krishna's body. Krishna became so huge that Kaliya had to release him. So Krishna saved himself from every attack, and when he saw the Brij folk were so much afraid he suddenly sprang into Kaliya's head and assumed the weight of the whole universe, and danced on the naga's heads, beating time with his feet. Then Kaliya began to die. But then the naga's wives came and prayed to Krishna with joined palms, worshipping Krishna and praying for their husband.
Kaliya, recognizing the greatness of Krishna, surrendered, promising he would not harass anybody. So Krishna pardoned him and then let him go free to leave the river and go

^{Here we see Krishna's Battle with the Demon Kaliya}