Okay 766g makes more sense given his prior conditions, I take it she wasen't feeding him small rats for a very long time. Males tend to stay smaller the females and every ball python is not going to frow the same. I have a maler from '09 that are in the 900g range, and he is on small rats, his mom was just over 1500 grams. A picture would provide a better perspective on him being under weight.