Flame, there is a wiki. The adorable little eggs are pygmy eggs. If you get super lucky you could find a chicken egg. A chicken is one of the rarest "dragons" there are.
Ditto with the dinosaur eggs.
There is also the zombie and neglected dragons that are also extremely rare.
The process of getting them also has a high chance of killing the dragon.
Zombie dragons require the dragon to die and then be revived by another dragon. Can't remember the breed.