my uncle was hiking today when he came across a weird animal that looks like a werewolf!?

A coyote with mange? Animals with mange look a lot different than ones with fur. If he wasn't just joshing with you.

Since he didn't give a very good description and you have no photos.....

https://www.google.com/search?q=coyote+with+mange&biw=1344&bih=679&tbm=isch&tbo=u&source=univ&sa=X&sqi=2&ved=0ahUKEwjel-yT2__MAhUKE1IKHX-bAz8QsAQIGw

Without a photo, such a description is useless for any type of identification purpose. There is no such thing as a werewolf, so it is not that. Where in the world you are is a factor as to what he MIGHT have seen and mistaken for one. There is always the possibility that he ran across one of the many "furries" out there who take their "hobby" (obsession) really seriously.