[kitty00829]

This wolf-fish-bird creature (You name it ^^) is born underwater, but can live so high in the air that humans cannot survive there. It is born underwater because the gills develop first, the lungs take a month or so to develop. When underwater the two wings transform into fins for swimming and the tail becomes more like a paddle. The eyes,ears and nostrils get a protective layer to keep out water and the gills open up. When out of water the fins once more become wings and the tail grows feathers and becomes more streamline. The protective layer goves over the gills and the nose, eyes and ears open up.

There you go ^^ My drawing is rubbish but the idea is okay.

Edit: If you don't want this creature, I do ^^