I decided to check on all my neighbors in order to find those eggs that can be hatched on my own island. So far, I have gotten the following:
Mythic Air, Magma, Shadow
Observations: It is possible to hatch it more than twice; after trying a couple of times, it crashes sometimes.
Benefits: Get new monsters. For those repeated, they could only give you EXP or been sold to earn money if you hatch them and placed them in one of your habitats.