I was wondering, how they give birth to children? I don't think they do the same as mammals like a Minotaur. For exemple, I think Ushi-oni or Siren have eggs. So, they shouldn't have a belly button when we think about that.
How long is the pregnancy? Same as human because they're half-human, or it's not the same for every species?
In the case of the eggs, it mean, they have a looot of children?
I know it might be weird but I'm the kind of guy who think about this kind of stuff because I'm curious and I want to know what do you think about that.