"All the world will be your enemy, Prince with A Thousand Enemies. And when they catch you, they will kill you. But first they must catch you; digger, listener, runner, Prince with the swift warning. Be cunning, and full of tricks, and your people will never be destroyed.”
A band of adventurers set out from their home, heeding a prophetic warning of imminent destruction. They cross dangerous wilderness, surviving on their courage and wits. They find a new community, but quickly realize it's an illusion of security, as dangerous as the outside world. Pushing forward, they forge their own community. To grow their community further, they stage two capers to liberate new blood: one simple, and a second, far more elaborate. Both succeed, through cunning and courage, but the latter one brings war upon their home. Against impossible odds, they defend their community, and defeat the invaders. Succeeding in all that, they become the stuff of legend.
The fact that they're rabbits is incidental.
In fact, part of why this works so well for me is the characters truly are rabbits. They aren't anthropomorphized animals. No disrespect to Brian Jacques's Redwall series, but his mice and other animals live in a castle, harvest and cook food, use swords and other weapons. Richard Adams's rabbits may be exceptionally clever, even psychic in the case of Fiver, but they live and act as rabbits.
This book also gives a fantastic ensemble cast: Hazel, the brave leader with enough wisdom to know how to listen to his people; Bigwig, the warrior whose loyalty never wavers, who strives to become more than just muscle; Fiver, cursed with second sight; Blackberry, the clever one; Dandelion, the fastest and the storyteller; Bluebell, the jester, and more. Even beyond the Watership Down rabbits, there's Keehar, the gull they make into an ally, and General Woundwort, who is a fantastic antagonist. Even as he's defeated, he gets to be as much a myth as anyone else in the story.*
I've read this book more times than I can count. I've had two copies fall apart on me. I still re-read it on a regular basis. And I'm sure its fingerprints can be seen in most of what I write. The Thorn of Dentonhill surely has a bit of the spirit of Elhrairah in him. The Holver Alley Crew's plan is as impossible and daring as the raid on Efrafa. And you better believe that Dayne's heart in Way of the Shield is a match for Bigwig's. "I swore to my Chief Rabbit that I'd hold this run," is exactly the sort of thing he'd say.---
*- The 1977 animated movie is interesting but flawed, but it get's General Woundwort's end perfectly. The Nutinger Farm dog is tearing through Efrafan rabbits like paper, and Woundwort emerges from a hole, bloody and torn from his fight with Bigwig, and screams, "Come back, dogs aren't dangerous!" As he leaps in to take on the beast, the scene fades away. The fact that the dog tore him to shreds is irrelevant, and not something we need to see. The General fights to the end.