One day the Gopa boys went over to a tank to quench their thirst. They saw a huge monster in the form of a Baka (crane). It rushed forth and swallowed Krishna. Krishna caused a burning in its throat and the Asura threw him out. It made a second attack and Krishna held the two beaks and parted them asunder as if they were blades of grass, And the Asura died.
On the other day Krishna was playing with the boys in the forest. Agha, the youngest born of Putana and Baka, the Asura whom even the Devas, rendered immortal by Amrita, dreaded, burning with a spirit of revenge at the death of his brother and sister, thought of killing Krishna and all his attendants. He stretched himself forth as a huge serpent, spreading over one yojana, the extremities of his open mouth touching the clouds and the earth. The Gopa boys took the Asura to be the goddess of Vrindavana. “Or if it really be a serpent opening its mouth to kill us, it will instantly be killed like the Asura Vaka.” So with their eyes fixed on Krishna they clapped their hands and with a smile entered the mouth of the serpent, even before Krishna had time to warn them. The Asura still waited with its mouth open for Krishna. Krishna thought how he could kill the serpent and at the same time save his companions.
On reflection, he himself entered the mouth of the serpent and stretched himself and his comrades. The Asura lost breath and breathed his last. A shining spirit emerged from the Asura body and entered the body of Krishna. Krishna gave fresh life to his comrades by his Amrita bearing looks.
Krishna killed Agha that very day when Krishna entered his sixth year.