It would work kinda like this: When you create your creatures in sandbox mode you can give them last names (if you don't give them a last name it would just be blank) baby creatures would have the same last name as their parents, if both parents have different last names then the baby has a 50/50 chance to be born with either last name. Lone nichelings that you take in will have blank last names which you can edit. If a female gets pregnant from a rogue male the baby will have its mothers last name. If one parent doesn't have a last name the baby is born with the last name of whatever parent does have a last name and if both parents don't have last names then the baby won't have one either. I think this would be cool for story type things and it would be easier to know which creatures are related without having to search through the family tree. It would especially be helpful in large tribes.