How do I breed a Century dragon in Dragonvale?

Looking for the fastest combination to hatch the Century Dragon? Not a problem! Rejoice, the 100th dragon is upon us!

CenturyDragonAdult

Breeding Pair: Fog + Mountain OR Mud + Snow

Breeding Time: 10 hours

Availability: Til ~ May 18th per DragonVale Facebook Page (100 days)

Type: Earth, Cold, and Water

Price: 2,013 Gems (If I had a gem for every year... oh, wait...)

# Update:

As a result of the addition of Blizzard and River, the odds on the combos have changed a bit. I've updated with the new fastest combos, considering potential Blizzard and River outcomes.