Obsidian Dragon

Breeding
The can be bred by pairing two basic dragons (one Earth Dragon and one Fire Dragon) or two dragons that combine Earth, Fire, and at least one other element at the Breeding Cave/Epic Breeding Island.

Earning Rates
Coin per minute: Level 1: 5 / Level 10: 35

Dragon Earning Rates without boosts.

Boost Calculation Guide to use with the page linked above.