In 2001, director Richard Kelly shoot his movie "Donnie Darko". Watership Down exerted an significant influence on this movie as well. I want to amplify it a bit closer.
Besides Drew Barrymore and Patrick Swayze, Jake Gyllenhaal and his daughter Maggie are also scintillating in this movie.
In the movie, Donnie is able to travel into a parallel universe, where he has to accomplish serveral orders to finally save his universe. He's lead by Frank, who appears Donnie as a kind of huge zombie rabbit. According to Richard Kelly, this idea is based on the book Watership Down. This is not really surprising, because Frank could go for an anthropomorphic version of the Black Rabbit of Inlé.
In the director's cut of the movie, we also see a scene, where the pupils had to read the book Watership Down during the class hour. His teacher, Karen Porneroy says to Donnie: "Maybe you could read it together with Frank."
During the further course of events, the movie version of Watership Down is shown also during a lesson. After the movie has finished, a dialogue between Karen Porneroy, Donnie Darko and Gretchen Ross starts (looseley translated from the german version):
KP: "When Fiver is telling the other rabbits about his vision, do they believe him?"
DD: "Why is that bothering us?"
KP (sad): "Because we're the rabbits, Donnie."
DD: "But I don't grieve for a rabbit as for a human."
KP: "So the death of one species is less tragic than the death of another?"
DD: "Of course. Rabbits aren't like us. They've no history books, no photos. They know neither grief nor doubts. I mean, sorry, Ms. Pomeroy, don't get me wrong. Yes, I like rabbits, they're cute and always horny; and when you're only cute and always horny, then you could only be happy. Then, it's samey, who you are and why you live. Then, you just want to have sex, whenever you can, until you die. But because of that, you don't have to wail, just because the rabbit, who never feared death in the beginning, dies."
GR (looking saddened): "You're wrong. These rabbits could talk. They're living from the fantasy of the author and because they're touching him, they're touching us as well. Otherwise, we wouldn't have understand the movie."
(DD looking gloomy)
KP (sad): "Don't we forget the magic of story-
it can be said, that even Donnie has to acknowledge the Deus Ex Machina to understand, what's his duty in this parallel world. So, Watership Down in the Donnie Darko movie is virtually the manual to the solution of the parallel universe, or at least a hint for Donnie to prepare for his task.
He especially understands through Watership Down, that he must acquiesce to the rules of the tangent universe (as the parallel universe is called) to save his family and his universe.