Dragons are similar to the other Non-evolvable pets (Pu pet, Fox pet, Yun Sheng Beast, Alpaca) in the sense they start from level 60 and have no skills. They will also take up a pet slot, have loyalty, and can be ridden. They are obtainable from the Dragon Lucky Box.
Like Moon Wolves, Dragons can "evolve" to become True Dragons and Ultimate Dragons. True Dragons require two level 65 Dragons while Ultimate Dragons require two level 70 True Dragons. The primary difference is in their appearance, where they will get more colors and begin to glow. You will need the True and Ultimate Dragons Alchemy Scrolls from the Item mall to do this, based on their respective kind. Actual Alchemy or High level alchemy is not required for this.