The average dragons...
Plant, earth, fire, flower, lava, moss, poison, tree, cold, mountain, storm, lighting, firefly, quake, crystal, water, ice, mud, swamp, seaweed, air, sonic, snow, blazing, willow, fog, blue, fire, scorch and sandstorm.
Special dragons!
bone (breed fire and earth around Halloween). Moon (blue fire and storm after noon.) Sun (same before noon.) Reindeer (cold and plant near Christmas) Rainbow (lava and seaweed.) Iceberg (water and cold in the year of the dragon AKA 2012.) Panlong (must buy from the market in year of the dragon.)
You can't win in dragonvale, unless you consider collecting all the dragons a win.
All DragonVale hybrids are bred by picking two dragons of different elements to be bred with each other.
No dragons
You either breed them or buy them with coins and gems
There's over 1,000 types it's almost impossible to know them all!
No they are not.
No, DragonVale dragons are not able to be traded.
No, emerald dragons are not breedable with any dragon. This is true of all of the birthstone dragons.
level 10
You feed them dragon food.
All dragons are full adults at level 7
The dragons in DragonVale are not trainable. You only feed them to level them up and breed them.