Kansa knew that the eighth child, according to the prophecy, would be his slayer. When the eighth child was born to Devaki, Kansa immediately arrived at the prison and snatched the baby from Devaki. This was actually the goddess Yogmaya. She laughed at Kansa for his foolishness and told him that his slayer had been born and was living in Gokul.
Kansa was furious and ordered his men to kill all children born on the same day as Krishna, but the men returned empty-handed. Finally, Kansa sent Putana, the queen of the demons, to kill Krishna. She planned to kill him by feeding him poisoned milk.
Krishna was lying in the cot in the courtyard Nanda's house. Putana assumed the form of a beautiful maiden and happened to be passing by. When she saw Krishna, she asked for permission to pick him up. She offered her breast to feed him and Krishna sucked the life out from her.