Handicapped Badass: after he gets shot, his leg causes him infrequent pain and makes it difficult for him to run for the rest of his life. Within the plot he notes that this would normally end his rule as chief rabbit, if not get him exiled or killed, so the fact he keeps on acting as chief-rabbit is impressively badass.
Woundwort spares his life, considering him not worth killing. He don't even consider that he could be the chief rabbit because he is only of average size and walks with a slight limp, and this mistake ultimately dooms Woundwort.
Take a Third Option: Several times. In fact, one of the main reasons why he makes for such a good leader is his willingness to think outside the box and try new solutions.
Wide-Eyed Idealist: Many characters view him as this; even his own followers sometimes think he's too naive in his belief in the good of everyone. However, when it comes down to it he's usually right when he decides to trust someone.
Fiver
Hazel's brother, a prophet whose visions spur Hazel to leave.
The Cassandra: Subverted, somebody actually listens and some of them leave Sandleford Warren before it's too late. Furthermore, after the others realize his warning about the danger of Cowslip's Warren is on the money, his counsel effectively becomes Word Of God to them.
Cowardly Lion: While he cowers, shakes in fear and having to be coaxed going everywhere, it's also surprisingly a Moment of Awesome when he goes out on his own to find his brother, even though he knows fully well that his brother was shot.
Dissonant Serenity: His little chat with Vervain. Dear God. Fiver, previously thought to be dead by the Efrafrans suddenly sits there, calm, looking at them and then apologizes to Vervain for Vervain's imminent death. And continues to explain that after all it was their own fault. Since they came to kill the rabbits of the Watership Down warren... and he says this all in a very calm, serene, soft voice... while Vervain sees him surrounded by ghosts of 'rabbits done to death months before in the tunnels of Efrafa...' Fiver is a Freakin'. Damn. Scary. Fluffball.
Dream Land/Another Dimension: Fiver discusses the concept with Hazel, as Fiver travels in this land in a vision to find out what’s happened to Hazel after he goes missing. No-one doubts it’s existence because in Lapine mythology El-ahrairah moves between this place and "Another" at will, and Fiver is well aware of its existence from his visions, and claims that this spirit world is, in its own way, just as dangerous as the mundane one most rabbits know.
The Smart Guy: He's the rabbit that discovers the concept of floating. This bit of insight comes in handy later in the book.
Pipkin
The smallest and most timid of the rabbits, Pipkin is a friend of Fiver who is persuaded to go along on the journey.
Character Development: Though it mostly happens in the background, and in small ways, Pipkin does change and develop a lot over the book, starting out as afraid of everything and gradually becoming a loyal and steadfast companion.
Cheerful Child: The TV series not only portrays him as very young, but removes his timid nature as well, making him this.
Cowardly Lion: Timid and easily scared he may be, but thanks to his fierce loyalty to Hazel and Fiver he'll show surprising courage at times.
Tagalong Kid: More in the TV series than in the book.
Undying Loyalty: Towards Hazel. At one point Hazel is considering a suicide-mission into Efrafa to rescue Bigwig and Pipkin responds simply "I will go with you."
Dandelion
A fast runner and gifted storyteller, whose stories of El-ahrairah keep the spirits up among the rabbits (as well as giving the reader insight in Lapine mythology).
Composite Character: In the TV series, he has taken on most of Bluebell's character traits.
One of Bigwig's friends from the Sandleford Owsla, who is almost as big and good at fighting, but more placid and less hotheaded. He has gray fur, hence the name.
The Big Guy: He's the muscle of the team when Bigwig is incapitated, not available, or just not willing to follow orders.
Determinator: He certainly has shades of this, particularly when it comes to the defeat of Efrafa.
Noble Fugitive: Although Silver is the nephew of Threarah (the Chief Rabbit of the warren where the story begins), he joins Hazel's exodus and proves himself a skilled fighter and reliable follower.
The Tank / Meat Shield: The other rabbits rely on him for this as hlessil.
Buckthorn
Described as a "decent, straight-forward fellow," Buckthorn is an outskirter from Sandleford with a tough, sturdy and sensible nature.
Gentle Giant: Of the three Big Guys, Buckthorn is the gentlest and least inclined to fight.
Simple Minded Wisdom: Though he doesn't play the classic trope completely straight, since nobody thinks of him as an idiot and Hazel in fact deliberately labels him as the most sensible one in his crew. At the end of the book, he and Strawberry become Groundsel's chief advisors in the new warren.
Hawkbit
One of the outskirters from Sandleford who joins Hazel's crew. Described (by Hazel) as a rather slow, stupid rabbit, he is the first to complain and express doubt in Hazel's abilities as leader, but soon develops into a loyal follower — after which he's barely even mentioned by the narrative for the rest of the book. In the TV series, he has a dramatically increased role as the resident Eeyore.
Ascended Extra: He's an extremely minor character who is left out of every single adaptation of the book except the TV series, where he's one of the main characters.
Deadpan Snarker: Not in the book, but in the TV series he's developed a notable talent for sarcasms.
The Eeyore: He grows out of it in the book. In the series, not so much.
Two outskirters from Sandleford who join Hazel's crew. Apart from a few scenes and lines here and there, they don't get very much attention in the original novel — though Speedwell got A Day in the Limelight in the sequel, Tales From Watership Down.
A Day in the Limelight: Speedwell's Story from the sequel, a nonsense tale which Speedwell tells the other rabbits, is easily the book's Funny Moment (and usually the one part that even fans who didn't like the sequel enjoy).
Killed Off for Real: Not in the original novel, but in the sequel Acorn dies.
Red Shirt: Along with Hawkbit, they're really only in the story to fill out the number of rabbits — though it can be argued that Speedwell, thanks to the sequel has been upgraded to Mauve Shirt.
Head in the Sand Management: He was the Threarah's Captain of Owsla and tried to stop anyone from deserting the warren.
Heel Face Turn: In the beginning of the book, Holly tries to arrest Bigwig and Silver. He eventually ends up joining the group.
My Master, Right or Wrong: In a way he is the "good side" version of Campion, always sticks by his chief and is very efficient. He stuck by the Threarah, and when the Threarah died he stuck by Hazel.
Number Two: Described in the novel as a born second-in-command. He was the Threarah's Captain of Owsla and kept discipline in the Sandleford Warren. While serving Hazel he is still a loyal, no-nonsense, officer.
Another ex-member of the Sandleford Owsla, Bluebell survives the Sandleford Massacre and is the only one of Holly's group to make it to Watership Down.
Ascended Extra: Within the novel itself. He's literally a nameless extra in the first part of the book, but upon his re-introduction along with Holly in the second part, he gets not only a name and a characterization, but becomes one of the major characters. In the sequel he's also a constant presence, constantly joking and lightening the mood for the other rabbits when things get difficult.
Heel Face Turn: He follows Holly's, though unlike Holly he is not named and gets no characterization in the initial confrontation with Bigwig.
Motor Mouth: He's a chatterer, constantly joking and rambling on about nonsensical things — though his constant talking has a clear purpose, namely to relieve tension and encourage the others to forget how dire their situation really is.
Rhymes on a Dime: It becomes a minor Running Gag in the novel that Bluebell makes up some nonsense poem and Hazel, in Deadpan Snarker mode, finishes it with a biting final rhyme.
Wicked Cultured: poetry, rudimentary cave art, and other human-like mannerisms. And in every dramatization he speaks with a posh accent.
Strawberry
A rabbit who befriends the Sandleford group. He joins them when they depart.
Default To Good: After Nildro-hain, his mate, dies, Strawberry joins the heroes because he realises that they're his best chance to stay alive, and he doesn't want to stay in the place that would ignore the fact that his mate died.
Ascended Extra: A curious version in the TV series; he's not present for his original scenes, but in the third season he appears and gets a large role.
Evil Counterpart: Although he's not actually presented as evil, he's clearly the dark counterpart to Fiver, who is terrified at the truth of Silverweed's poetry. In the TV series, he has more of an antagonistic role, though as we find out, he's actually just misguided.
Fiver: "He smells like barley left out in the rain to rot. He smells like a mole that's wounded and can't get underground."
Hazel: "He smells like a big fat rabbit to me, with a lot of carrots inside."
The Fatalist: most prominent in Silverweed's poem.
Trapped in Another World: After Fiver travels in "another place" to find Hazel after he's gone missing, he Tells Hazel that the “other place” exists, and is just as dangerous as the mundane world, if not more so. He then mentions Silverweed and states that:
Dying Moment of Awesome: In-universe example. Defeating Watership Down would have left him a tyrant: being defeated would have marked him a failure. Taking A Third Option made him a legend.
Such was Woundword's monument; and perhaps it would not have displeased him.
A smart and sensible doe from Efrafa, one of Bigwig's main helpers in the revolt against Woundwort. Like Fiver, she is a prophet who sometimes has visions of the future, though unlike him she isn't alway certain she's right.
Action Girl: Less so in the novel than in the film, though she has her moments. In the TV series, she's named Primrose.
The Cassandra: In an interesting variant, she manages to dismiss her own visions as being too ludicrous, even though they turn out to be completely accurate.
The Chick: She's the primary female character, as Clover drops out of the third act.
Damsel in Distress: In the book, Hyzenthlay nearly dies of grief after despairing of ever leaving Efrafa.
Love Interest: Not so much in the original book; she bonds with Bigwig and it's implied, rather than outright stated, that she eventually becomes Hazel's mate, but this is notably downplayed. In the TV series, she is definitely Hazel's Love Interest. In the film, she appears to be Bigwig's Love Interest. Of course, these are rabbits we're talking about here...
Captain Campion
A prominent rabbit in Efrafa, Campion is an enemy of the Watership Down rabbits and an important soldier of Woundwort.
An Efrafan officer, who despite his obvious hero worship of Woundwort, is a skilled, sensible and decent rabbit.
Heel Face Turn: He surrenders to the Watership rabbits towards the end and eventually becomes the Chief Rabbit of Vleflain, a new warren that's established between Watership and Efrafa and is populated by rabbits from both warrens.
Hero Worshipper: To Woundwort (even after his Heel Face Turn he speaks of Woundwort with awe), although he is far more competent and practical-minded than most other examples of this trope.
An Anglicized rendering of the rabbit term elil-hrair-rah, "thousand-enemies-prince." The rabbit folk-hero, El-ahrairah is the protagonist of most if not all of their stories.
Jerk with a Heart of Gold: Sometimes lapses into true Jerkass status, especially in the first story, but as a rule he is genuinely concerned with the well-being of his people.
Jesus: The rabbit equivalent, anyway. As you can probably tell, though, he is very different from the biblical Jesus.
Nice Job Breaking It, Hero: His arrogance is what curses the rabbits to be hunted in the rabbit mythology.
Sympathetic Inspector Antagonist: He's genuinely trying to keep the peace and be a good ruler for everyone in Frith's stead, though he develops a personal vendetta against El-ahrairah, who just keeps making trouble.
Well-Intentioned Extremist: At least from the rabbits' point of view, a lot of his attempts to keep El-ahrairah in check are unnecessarily cruel.
The Black Rabbit of Inlé
The rabbit Grim Reaper.
Dark Is Not Evil / Everybody Hates Hades: He is not a force of evil (he is one of Lord Frith's servants after all), but he is very creepy and nobody really likes him anyway.
Really? Cause at the end of the movie when he comes to take Hazel at the end of his days, he's actually quite comforting and nice.
In the novel, it was El-ahrairah who came to Hazel and asked him to join his Owsla - although that does beg the question of why the Black Rabbit did not appear... unless the two are actually one and the same.
The Dreaded: The Black Rabbit of Inlé is not evil, but in the book he is terrifying. In his presence even El-ahrairah cannot think straight, and therefore loses all of the Black Rabbit's games.
Viewers Are Morons: In the movie, he's called "The Black Rabbit of Death."
Only in the prologue; when Bigwig hears Captain Holly calling to him from afar, he whispers fearfully, "It's the Black Rabbit of Inlé!".
Hufsa
A rabbit who is planted in El-ahrairah's warren as a spy for Prince Rainbow, and thwarts many of El-ahrairah's plans before he's found out.
Cassandra Truth: El-ahraira envokes this in order to get rid of him. How do you discredit a spy? By implying to everyone that he's crazy, and then have him "prove" to them that he is when he tells of the many unbeliveable situations he's been in, that you secretly set up.
The Quisling: To rabbits, his name is synonymous with "traitor."
Other
Kehaar
A black-headed gull, Kehaar is befriended by Hazel and becomes a very important ally.
Badass: Notably, he fought off the cat that injured his wing. Demonstrated elsewhere in the story as well.
Giant Flyer: Sort of. Black-headed gulls are quite small birds, but he's huge from a rabbit's point of view. Used to great advantage on the Efrafa Warren raid.
Plucky Comic Relief: In the movie and TV series; to a lesser extent in the novel.
Put on a Bus: As a way of Holding Back the Phlebotinum, he leaves for the Big Water after helping the rabbits escape from Efrafa, and so isn't there to help them in the last battle. In the movie, his departure doubles as Shoo Out the Clowns.