It is a very good piece of work, the colors you used look amazing together. They don't clash or run into each other, and appeal very nicely to the viewer's eyes. I haven't seen anything like this, at least not using the same animal but the same technique. I like how there is a description of the animal you gave, so it is not just a pretty thing to look at and level up. I haven't seen this egg/growing technique thing many times on deviant art but I have on other sites so I will give you that. I also get what it is, and what its supposed to do and how, by using the information given and just based on what it looks like, so to me its pretty logical in my head for everything to be the way it is. Overall I think you did a wonderful job on it, making each phase adorable. I wish you lucks on having people "adopt" these.