Vervain is the captain of the Efrafan Owslafa. A very large, fierce rabbit, Vervain participated in the siege of Watership Down, but became terrified when a cornered Fiver predicted he would die. Although Vervain survived the initial attack upon the Efrafans by the dog, he did not return to Efrafa with Captain Campion and it is assumed he either ran away or was killed by predators during the journey home.
Watership Down (Film)
Vervain is an officer in the Efrafan Owsla who is mentioned but never actually identified.
Watership Down (Series)
Vervain is Campion's second-in-command. An extremely cruel rabbit, Vervain delighted in tormenting the "lesser" Efrafans under his and Campion's jurisdiction. Despite his bullying nature, Vervain was really a coward. He was accompanied at all times by his own personal bodyguards, Igg and Ook, and constantly abandoned his comrades in times of danger, a habit that almost got him executed by General Woundwort.
Following the liberation of Efrafa, Vervain was so hated by both the former Efrafan Owsla and by the rest of the Efrafans that he could not be assimilated into their new home on Watership Down, so instead he accompanied Woundwort first to Redstone (where he used the alias Chafe) and then to Darkhaven.
He proved to be a pretty useless clod, giving up his newfound position as Woundwort's second-in-command to Granite, until he "defeated" Granite and "won" his old job back. When Woundwort and most of the Darkhaven rabbits were done in by the power of the Black Rabbit of Inle, Vervain managed to escape and hasn't been seen