Sergeant Wonwill was a boxing hare in the Long Patrol under Lady Melesme. He was allegedly given his name because "if his right paw didn't get you, his left one will." Sergeant Wonwill was known to give out nearly constant orders while the Long Patrol was marching, but Wild Doogy Plumm said that he was all bark and no bite.
It was his idea for Doogy and Ferdimond de Mayne to sort out their problems with a boxing match; an exhibition of what he called "the noble h'art."
Wonwill was the strong right paw of Brigadier Buckworthy Crumshaw. He and Crumshaw were with the half of the patrol that stayed to defend Redwall Abbey, while the other half set off after Gulo the Savage. During this time, Wonwill assisted in the capture of the fox named Fargil, whom he faced unarmed and boxed to unconsciousness. Wonwill allowed Fargil to live, and sent him back to Captain Zerig, whose patrol was besieging the Abbey at that time. Under Wonwill's orders, Fargil told Zerig that, if the fox didn't surrender, the hares would meet the vermin in battle the following day.
As Brigadier Crumshaw was too injured to battle, Wonwill and Captain Derron Fortindom decided to lead the charge; Crumshaw protested, and Wonwill was compelled to knock him unconscious to prevent his doing something foolish. When Wonwill and Fortindom charged the vermin, they found that the enemy had placed decoys and that a few of them, led by Freeta, were sneaking into the Abbey. They were spotted by the Redwallers, and the Brigadier, who regained consciouness in time to attack them and halt the invasion. Crumshaw died in the battle; this left Wonwill and Fortindom in charge of the Patrol, and they proceeded to set a trap for Zerig and the rest of the horde, who planned to walk in the opened Redwall gate and attack unarmed mice. Faced instead by the hares, Zerig and his command were all killed.
Wonwill survived the war against Gulo the Savage and returned to Salamandastron; Melanda MacBurl mentioned meeting him in her chronicle.