It's worth noting that there is an excellent animated film of Watership Down. The main animation style is pretty good, and there are occasional dream sequences done in a more simple form that are fairly effective. For the most part it's a good film for children or adults, but the fighting at the end gets pretty graphic, including frothing at the mouth and blood. I'd put it in the same category for quality and violence as The Secret of NIMH. I saw the movie as a kid and later read the book in high school.

I intend to add more to this WU if I can find a copy of the movie.