To Breed Cythus, you need to have a Male and a Female Cythu, (You don't have to own the two, you can breed with someone else's) if there are any artists open for breedings, then you can PM them and ask for a breeding. If you and another person breed your Cythus, you get an Egg each, but if you breed two of your own, you only get one, and the other would possibly go up for adoption. ^^
Hope this helped.~
Haha..~ I can hardly wait~