Grumby was a young male hare cadet who served as Galloper in the Long Patrol, under the leadership of Lady Violet Wildstripe.
When Lady Violet took the young cadets on an overnight patrol, Major Felton Fforbes put Grumby, Folderum, and Frubbs Minor on sentry duty. Grumby became thirsty during the night, and wandered off to a nearby brook to drink; he was subsequently captured by a small band of vermin from the crew of Razzid Wearat. Seeing his friend in trouble, Folderum recklessly charged in and provided a diversion, which lasted long enough for the weaponless Grumby to seize up a rock and attack the the vermin with it. When the rest of the hares arrived, the vermin fled; however, the hares outran them, then turned to face them, Grumby still wielding his piece of rock as he charged with the others at his fleeing foe.
Not the be confused with Grumby.