Bone Dragon

Breeding
The can be bred by selecting a fire dragon to mate with an earth dragon at the Breeding Cave/Epic Breeding Island.

Breeding a fire dragon with an earth dragon can also result in a Lava Dragon.  EXPIRED 

Earning Rates
Coin per minute: Level 1: 6 / Level 10: 42

Dragon Earning Rates without boosts.

Boost Calculation Guide to use with the page linked above.