Ferdimond De Mayne was a young hare of the Long Patrol under Lady Melesme. He and Wild Doogy Plumm originally didn't get off on the right foot, as they were always getting on each others' nerves. Sergeant Wonwill decided to have them settle the dispute with a boxing match. The two fought on heroically, losing teeth and being bruised until their eyes were swollen shut. The match ended in a tie, with Doogy and Ferdimond being friends afterwards.
Later, as mentioned by Melanda MacBurl, Ferdy married Kersey, a pretty young Long Patrol hare. Earlier in the book she gave him her brother's sling and said that she wished to see him again. Kersey is otherwise known in the book for having lost her twin brother, Dauncey, in an ambush of arrows. Kersey gave birth to a son whom the couple named Dauncey de Mayne in memory of Kersey's twin.