Looking for the fastest breeding combination to hatch the River Dragon? Grab an intertube! We've got all of the details you need to know below:
Breeding Pair: Earth + Water (Another easy one, Backflip must be feeling guilty...)
Breeding Time: 13hours or 10 hours 24 min (with upgrade)
Availability: Unlimited
Type: Water, Earth
Price: 900 Gems (Would you accept an IOU?)
Note that this dragon is a possible outcome of attempts to breed the Century Dragon, so if you are working on that one, you might get this one for free.