Beauclair Fethringsol Cosfortingham, also known as Beau, was a hare, and a friend of Luke the Warrior. He was seldom called by his full name, which he could not remember until someone told him.
Beau was a slave for two seasons on the Goreleech. Thrown into the sea when he became too weak, he washed up on an isle inhabited by savage vermin, but held them off by using his talents of disguise and throwing his voice. The vermin believed he was an island spirit called "Werragoola" and largely left him in peace. Beau also grew fresh fruit on the island for himself. None of his earlier history is known. Luke and his friends discovered Beau stranded there, and let him join the crew of the Sayna.
Like many hares, Beau enjoyed singing raucous ballads and scarfing down food. He exceled in the culinary arts, and was immediately elected to replace Cardo, who was the ship's current cook. However, to spare Cardo's feelings, Beau appointed Cardo as his assistant and the two became friends.
While following the Goreleech, Beau was swept overboard during a storm. Cardo grieved Beau's loss, but the hare ended up on an island, this time the lee side of one of the Twin Islands. He was reunited with his friend Vurg after the Sayna's shipwreck. The pair tried to create a raft with little success, until Bolwag arrived. The sea lion helped them finish the raft and towed them to the Goreleech. There, the pair plagued the Goreleech, acting as "Sea Bogles" and stealing the corsairs' food. They also prepared the slaves of Vilu Daskar for the mutiny which followed.
Beau fought alongside his friends in the mutiny, and was one of the few who survived when the Goreleech split apart. He lived on the half of the ship rammed up on a rock with Vurg, Dulam, and Denno dubbing the half of the ship, Arfship. Martin the Warrior and company found them still living there many seasons later. Beau then journeyed to Redwall Abbey with Martin, Trimp, Gonff the Mousethief, and Young Dinny, where it is presumed he lived out his later seasons.