8 Hours
KP combo: Poseidon/Forest
Androids can buy the Olympus for coins in the market, then use it in breeding to get this dragon.
Elsa edit:
Olympus type does not break down into other colors. This means that the Olympus type doesn't contribute to the pool of possible babies in your efforts for other Dragons. However, if you breed Olympus with a type that doesn't give you an Olympus hybrid, it'll rain Fire Dragons. Which is by design. ;D