Talk:Game Updates/@comment-4838403-20130822203143/@comment-4738639-20130822214045

The Moon Dragon and Sun Dragon runs on the internal clock of the device being used. Those icons in the menu show that Moon has to be bred at night and Sun has to bred at day.

I'm not really sure why some are locked and some aren't. I think if a dragon is displayed then you can view the hint for free, but if it isn't then you have an option to purchase the hint.