Wookies are hairy humanoid creatures who come from the forest planet of Kashyyyk. They take the side of the Old Republic during the Clone Wars. The most famous Wookie is Chewbacca who is the co-pilot of the Millenium Falcon and friend of Han Solo.
Even though Wookies only groan, they are able to understand humans and humans are able to interprete their groans. Wookies are highly intelligent despite their method of communication.