upon landing on earth, krypto is a fully grown dog, possessed of superpowers similar to those of superman's (since all kryptonian life-forms gain superpowers from exposure to a yellow sun, such as earth's sun). later, krypto is adopted by kevin whitney, a 9-year-old boy, with whom superman arranges for him to stay (as superman himself is often too busy saving the world to take care of him). krypto poses as an ordinary dog while living with kevin's family, but adopts the secret identity of krypto the superdog for his superheroic deeds; kevin is aware of krypto's dual identity, but the rest of kevin's family is not (excluding kevin's spoiled cousin bailey, however accidental). kevin lives next door to andrea, a girl who takes care of streaky.