Pixar's approach to their character design and environment designs is definitely influenced by earlier Disney animation films in terms of the shape language. I would suggest studying those as a starting point.
Just some really quick doodles for this weekend. Went to see zootopia this weekend. Great film and the characters are awesome. so I sketched a few a few in a Disney infinity style.
So as a small summer project I have decided model the Uylesses, which is the submarine from Disney's Atlantis. Here are some reference images to get you going :D http://imgur.com/a/DjlxI
I'd say eyes look off. Depending on what you are going for, the eyes make it look like the turtle is in some Disney movie and is going to start talking to me.
What you are seeing is probably ue4s change to the disney diffuse model instead of lambert. "New: Switched diffuse shading model from Lambert to energy conserving Burley."
Something that would really help is to study anatomy and draw through. Look through the comprehensive work done in disney life drawing courses, and the drawing manual of Glenn Vilppu.
I agree with Sectaurs, let's see some close ups on that face! The style/proportions are really cool, a very Disney like feel to the whole thing. Keep going with this!
Before and after showing a total redo of an old model (character is from "The Ballad of Nessie" by Disney). I did the old version when I first started teaching myself to sculpt.
Victorian Disney style would be amazing or like a steam punk Victorian would be cool to (though i accidentally voted for biosphere rather than Victorian.. way to pay attention lol)