In the release notes:Many Crowns pets will be ineligible from Hatchmaking, but may make an appearance in the future! Note that if a Crowns pet is already listed in your Pet Tome, there will be no Crowns cost for hatching that pet. But when I look in the kiosk, at "My hatches," there is a Sultan's Monkey pet that someone used to hatch with my pet, and if I want to hatch with it, it will cost me 850 crowns. I already have a Sultan's Monkey and it's listed in my Pet Tome, meaning that it shouldn't cost me any crowns to hatch.