Mood in Watership Down is rife with anxiety and tension, derivative of the high-stress situations Hazel and his fellow travelers endure. This mood is also a product of the rabbits' natural behaviors. They are prey animals, and thus remain hyperaware of their surroundings, always on the lookout for danger. While the novel concludes on a hopeful, contented note, danger is an omnipresent concern, lending much of the text a foreboding air.
This foreboding air is overwhelmingly due to Fiver's premonitions of danger, which shape much of the novel's plot and forward narrative progression. Whenever the rabbits feel that they are safe, Fiver is there to warn them about a new danger on the horizon. The rabbits cannot rest; it appears as though the whole world is out to get them.
The reality of omnipresent danger in Watership Down even works its way into the rabbits' religious beliefs. Unsurprisingly, rabbits believe their persecution is the result of a conflict amongst gods—a cosmic punishment, from which their only respite is the speed and craftiness gifted to them out of sympathy. The foreboding mood dominates even in religion, then; and yet there is still hope. Every day, rabbits escape the jaws of death, possessed of the ability to trick even the wiliest of enemies.