HE'S TOO YOUNG TO HAVE BABIES TF????

By human standards, yes but by animal standards no. Also, he wanted to have a kid all along, just he never knew he could carry one himself..

If you check on chapter 1 he be 19 years old (canon partner also around same age) and if you think about it he went to the big city to make babies himself and get other human males preggi XD never would he knew he’d conceive them himself hahha (≧∀≦) them being beastman might also help the fact that they want to populate soon cuz of their declining birth rate