Bigwig was a large and strong rabbit known for the tuft of hair on his head. His lapine name is 'Thlayli' which, translated literally, means 'fur-head'. He was part of the Sandleford Owsla with his friend Silver. He, with several others left with Hazel and Fiver. Because of his stubborn nature Hazel hesitated at first to bring him along, thinking Bigwig might be a bully and trouble maker. Luckily for all Bigwig left with them anyway and proved to be one of the most valuable members of the party. Bigwig is notably the strongest of the Sandleford rabbits and an accomplished fighter. He survives two normally fatal situations, being snared in Cowslip's Warren and a brutal fight with General Woundwort, and is very brave.
Along with his strength Bigwig has a short temper, especially for those who question authority he condones such as when Hawkbit, Acorn and Speedwell threaten Hazel's authority. Despite that he is not blind concerning those in power, he knows well enough when it is time to leave the Sandleford Warren and would never submit to the authority of a tyrant such as Woundwort.
Bigwig is one of the more superstitious rabbits. He values stories and is irritated by Cowslip's Warrens dismissal of them. Upon hearing Captain Holly call his name in the night, Bigwig is convinced the Black Rabbit of Inle has come to take him away. He also curses General Woundwort in El-ahrairah's name. Despite this he initially was very cynical of Fiver's visions, especially in Cowslip's Warren. His encounter with the snare changed his mind, however, and for the rest of the novel Bigwig is a believer.
Bigwig forms the closest relationship with the gull Kehaar. He is entranced by the bird's stories of the ocean.
In the film version Bigwig is depicted, as most of the characters, in a fairly realistic manner. His distinctive tuft of fur is darker than his body. He is one of the larger, stockier rabbits and often has claws.
In the TV series, Bigwig is a large grey hare-lionhead rabbit mix. He at first questions Hazel's authority, but later on admits that Hazel was the one who had brought them to the down making him the leader. Unlike in the novel Bigwig is considered Hazel's right-hand rabbit, military adviser, and Captain of the Owsla.
He is much more of a bully in the TV series than in the novel and film, but also more caring especially when Pipkin becomes frightened after a weasel nearly killed him. His strength also makes him a great swimmer. Also, he is a strict follower of the Owsla Code of Honor, which dictates that when an Owsla member is defeated, he must accept that defeat whether it was fair or not.
In Episode 10 of season 3, Bigwig falls for a doe named Spartina, but little did he know that she was a spy for Woundwort, and when the secret was revealed by Silverweed, Bigwig was angry, and even after Silverweed showed him her heart, he still distrusts her, at one point telling Hazel that he followed his heart with Spartina, and she was a spy. However, when Spartina goes back to Darkhaven, he asks if she will come back to him, which she says she will, and it is assumed that Bigwig and Spartina settle down together.
Bigwig is known for for being stubborn and tends to act before the thinks. He can be very short tempered and a bit of bully, especially if things don't go the way he likes or when when others question him. Bigwig is not a blind follower, and will only follow those he believes are true leaders who do right for their warren. At first, especially shown in the TV series, he appeared to value rabbit traditions greatly, and doing things, such as allying with other animals, or bucks digging unatural and at first refused to accept them. Bigwig seems to possibly have a degree of sexism, as show in TV series and Tales from Watership Down. He first refused to help Blackberry (who is a doe in the TV Series) dig, despite obviously that she is the only doe and needs help, simple thinking it's a doe's job to dig. In Tales from Watership Down he seemed to dislike the idea of a doe being a chief of a warren, possibly because most chiefs are bucks. Despite his temperament, Bigwig can show soft sides, such as when Hannah goes missing in "Bigwig's way", he desperately attempts to find her, or sometimes soften when Pipkin is danger. Bigwig is still very loyal to Hazel and would go to great lengths to defend his warren.
- Bigwig has a love interest named Spartina.
- Bigwig's lapine name is Thlayli which means fur-head.
- Bigwig's weakness is he has strong romantic feelings towards Spartina.