Wikia

Bone Dragon
Adult Adult - Juvenile Juvenile - Baby Baby - Egg Egg		Available	Level 7
		Buy	25
		Sell	5,000
		EXP	4,500
		Breeding Times	10 Hours
		Breeding Times	8 Hours
		Incubation Time	10 Hours
Habitats	Fire, Earth	Boost
Limited:	EXPIRED	Boost
Game Description
Bone dragons can only be found for a couple weeks during the year. The rest of the year it is believed that they burrow underground near cemeteries to be around other bones. But I bet if you breed one and put it in a habitat with other bones, it would stick around. Or perhaps near a heat source to keep away the bone-chilling winter cold?

Breeding

Coin per minute:

Lvl. 1	Lvl. 2	Lvl. 3	Lvl. 4	Lvl. 5	Lvl. 6	Lvl. 7	Lvl. 8	Lvl. 9	Lvl. 10
7	11	15	19	23	27	31	35	39	43
Lvl. 11	Lvl. 12	Lvl. 13	Lvl. 14	Lvl. 15	Lvl. 16	Lvl. 17	Lvl. 18	Lvl. 19	Lvl. 20
47	51	55	59	63	67	71	75	79	83

Dragon Earning Rates without boosts.

Boost Calculation Guide to use with the page linked above.

The Bone Dragon was the first dragon to be have its own limited decoration.
The Bone Dragon is the first Limited Dragon to be officially re-released. (The Firework Dragon was made available on Aug 22, 2012 after being expired, although this was assumed to be a game glitch.)
The baby Bone Dragon's appearance in the game differs from the one in the sneak peek on DragonVale's Facebook Page.
When the Bone Dragon was initially released, it was impossible to tell if you had bred a Bone Dragon or a Lava Dragon until you hatched the egg, as they both used the Lava Dragon egg.
- The egg for the Bone Dragon was changed to the current version when the Bone Dragon first left the market.
The Bone Dragon has the lowest purchase and selling price of all the Limited Dragons.