Beorn is doable. He's just a "golden compass" black bear that is sometimes man, sometimes bear. The morphing part shouldn't be an issue.
In the for what it's worth category, I play Lord of the Rings online...besides the fact that I run into the main characters on occasion, one of the most fun moments was very early on after release and my RL wife an me were exploring. We found the spot where Bilbo got the trolls "stoned". It was very satisfying on a number of levels. The game is quite true to the books, I've enjoyed playing it.
His intelligent animals would present the most difficult part I think. As I recall he had a house full of animal servants.