You were right, it’s not the same species as the other eggs. So if it’s not a dragon, what is it?

And look, it’s gotten bigger! Maybe it will reach its full size soon.

This charming little creature's full name is Lord Wakka Wakka Foo Foo Frederick the IV, after his esteemed father and grandfather and so on, etc., etc. He comes from a line of dignified nobles who were put under a terrible curse when his ancestors offended a magi dragon; their instincts forced them to helplessly devour the food items he had been so carefully experimenting on for the last thousand years of his life. The curse he placed on them was that of giving everything around them extravagant, ridiculously long titles. Afflicted as were all his forefathers, poor Frederick thus calls lunch 'that Meal Before Supper After Breakfast When the Sun is High,' and calls the sky 'that Vast and Unimaginable Expanse of Various Gaseous Molecules.' Although he is very polite and lovely company, whoever tries to talk with him often goes insane because of all his extended names for things.