Brother Hollyberry was a kind male mouse and the keeper of the infirmary at Redwall Abbey. In his youth he was very mischievous and was known as "Hollyberry the Horrible"; Abbot Saxtus often claimed that Hollyberry's antics were the reason he was "gray and bent double", as Hollyberry himself put it. He slept in the armchair in the infirmary and he also liked the otters' hotroot soup.
When Samkim and Arula were being punished for carelessly shooting arrows by being sent to the infirmary, Hollyberry was very nice to them and instead of making them work, allowed them to play a game and eat candied chestnuts. Hollyberry later cared for creatures who had Dryditch Fever, though became ill himself. He made a full recovery when Thrugg and Dumble returned with the cure, Flowers of Icetor.