Sketchy skeleton idea number two. When Reshiram is an ancient chicken with canine head, Zekrom is more like humanoid reptile.
So yes. Zekrom's skin is a such stiff and keratinous. His hands are actually those small claws, but he has big fake claws made of keratin and gristle that make his hands looks larger. His head crest has also similar story, with some eletric component inside that conduct electricity to his head light. Tail is stiff and carries the weight of turbine elements revolved around it. Teeth are different size [every time you see Zekrom roar in the movies, just four lower and two upper teeth are seen].
Weird and not 100% mistakefree, but I kinda like it.