Because Altman has children like humans, Altman in the bright country is human, and he became Altman only because he was irradiated by the plasma spark tower. For this past, Altman's cartoon explained in detail that when the solar energy of Otto was exhausted, scientists in the country of light created an artificial solar plasma spark tower. I didn't expect the plasma spark tower to be tampered with by aliens. After being radiated, the human beings on Otto became Altman with special abilities.
All human beings in the bright country can become Altman, or they can change back from Altman to human form. The Otto brothers have appeared in the country of light in human form many times, so as long as Altman wants to reproduce, he just needs to change back to human form and be like normal human beings.