So you came here, and you wondered... "What the hell is a Wisent?"
Well, they're pretty much like cows. Except more awesome. And they also live in Europe. In fact, you can think of them as the European Bison (Ooooh, I see!) which is related to the American Bison... commonly known as buffalo.
It should really be obvious now why the addon is called Wisent. So, uhm... let me just say that the actual buffalo is the African Bison, which is the most awesomest of all. But that makes for a pretty bad addon name, doesn't it?