There are three types of dragons eggs:

Orange Egg - Neutral Dragons:
Cost $150,000 (Level 50 or above). Eggs sell for $70,000 each.
Hatches into a Crystal, Yellow Jade, Purple Jade, Blue Treasure, Crystal Jade or White Dragon.

Brown Egg - Evil Dragons:
Cost $200,000 (Level 55 or above). Eggs sell for $110,000 each.
Hatch into Green, Blue, Red, or Black Dragon

Blue Egg - Upright Dragons:
Cost 1,000 Papayas (Level 60 or above). Eggs sell for $150,000 each.
Hatch into Brass, Bronze, Gold or Silver Dragon.

Dragons can attack each other or other farm animals. When they mature, you can send them to attack a friendâ??s ranch. If the ranch does not have any dragons guarding it there is the possibility that you will get some money.