I want to get the Yule Dragon and I wanted to find out how to breed it. I went on the DragonVale Sandbox to find what dragons have the best possibility to have a Yule Dragon as an offspring. It turns out the best combination is Harmony and Mountain Sun. I have a Harmony Dragon but I don't have the Mountain Sun Dragon. If anyone has the Mountain Sun Dragon and wants to co-op breed then add me and also put your Friend ID in the comments. My Friend ID is EthliRealms#3379