Yes, this is possible. You could theoretically code things so that the offspring of two parents hatch in a different form, or even a completely different species if the parents have a particular sign or combination of signs. You can get as complicated with this as you want, really. Here's a link to a post I made a while back, responding to someone with a similar question as you. I provided a lot of examples of complex breeding combinations that might give you an idea of what's possible.