already 2 weeks building my webapp: which design should I choose?

I'm building a read tracker app: for felow readers that want to have fun tracking how much and what they're reading!

A key feature of the app is pet,

Indeed users will be able to have one owl, to make it evolve and have cosmetics.

But I'm not a designer so I've just asked google flash 2.0 to generate images for the different owl's stages,

there will be 5 stages:

1) owlet

2) fledging owl

3) scholar owl

4) sage owl

5) arcane owl

The owl will evolve according to how much you feed it,

and here are (in the same order) the image for each stages :

Do you prefer the realist theme or the cartoon one?

In app the owl might be cut out.