Watership Down is the tale of a group of rabbits in search of a home. Fiver, a small, young rabbit, has a gift: He can tell when things are going to happen and he can sense whether they will be good or bad. Fiver foresees great danger to the rabbits' home warren.
Written by Richard Adams and first published in 1972. In 1996, Richard Adams wrote a sequel Tales from Watership Down which consisted of 19 short stories.
Cel animated movie released in 1978. It stays true to the book fairly well for a movie, and kept the most important parts as-is.
3 season long tv show from 1999-2001. It is a more child-friendly adaptation of Watership Down with some new stories, characters, and events that weren't seen in the book or movie.
BBC Radio 4's adaptation of Watership Down in a 2 part radio drama. Each part is 1 hour long.
Currently in production, the new CGI mini-series based on the book is rumored to be darker, but less gory, than the original movie.