Kamsa, the evil uncle of Krishna came to know that Krishna was in Gokul. He summoned all his demons and commanded them to go and kill Krishna. Krishna, who is none other than God Himself, killed all those demons. In the end, Kamsa was also killed by Krishna, as predicted by the unknown voice. Besides killing all the demons, Krishna also performed many wonderful feats.
The first one to go was Putana, who was a dangerous demoniac witch. Kamsa ordered her to kill Lord Krishna. Krishna was only a few months old. Putana, took the form of a beautiful woman and planned on getting rid of Krishna by feeding him with her poisonous milk. Krishna took hold of her breast, sqeezed it very hard with both his hands and sucked out both the poison and her life.
When her gigantic body fell to the ground, it smashed all the trees within a limit of twelve miles. They found baby Krishna playing on her.
When the cowherd men chopped her huge body with axes and burned the pieces of her body in fire, the smoke filled the air with a very pleasing fragrance.
If something good is to happen, it always will. Good will always prevail over evil.