It’s notable that in His original form Krsna is ten years of age. “Then, at the age of ten years and seven months, on the eleventh lunar day of the dark fortnight of the month of Caitra, He went to Mathura, and on the fourteenth day thereafter He killed Kamsa. Thus He completed His kaisora period at age ten, and He eternally remains at that age. In other words, we should understand that from this point that the Lord remains forever a kisora.” Thus Srila Visvanatha Cakravarti comments on text 45 of the tenth chapter in Canto Ten of Srimad Bhagavatam.