On human-whatever-species-else hybrids

I’m kinda curious about this concept and got more into it after reading James Patterson’s Maximum Ride: The Angel Experiment.

People, uhm, scientists from Britain managed to prove that hybrid species is a possibility. They were able to create a 32-celled human-bovine embryo and are working to improve it. To the scientists, would-be scientists, wannabe scientists, this:

“Can the evince of both species features be manipulated?”

I mean, like in Maximum Ride, the human-avian hybrids were perfect in a sense that only the “wanted” features manifested. They didn’t look like ugly mistakes of genetic engineering. I mean, can genetic engineering really reach that? Some recombinant life forms mentioned in Maximum Ride didn’t look so ugly – as defined. The director of ITEX, a human-galapagos tortoise hybrid, was perfect in a sense that it didn’t have tortoise-like body or something.

I guess, without much manipulation of the embryo, those recombinant life-forms would have looked hideous. They could have had bird feet, feathers all over their bodies, beaks, shells and whatever else unsightly. They would have looked like… mistakes; like some other recombinants mentioned.

Now that’s what makes me wonder. And I want answers, explanations, or something.

Can genetic engineering really do that?