Rockjaw Grang was a male hare of the Long Patrol under Lady Cregga Rose Eyes, having originated from the Northlands; due to his great size, he was sometimes referred to as the "Giant of the North". Despite his fearsome appearance, he was a gentle giant with Dibbuns. He was the eldest son of Goodwife Grang. He was deadly accurate with his massive yew longbow, and was popular with many members of the Long Patrol; due to his great size, he could kill some foebeasts simply by kicking them in the neck. He was known to have a pronounced accent, indicating his origin in the Northlands.
Rockjaw was a member of Major Perigord Habile Sinistra's patrol. When Tammo and Midge Manycoats infiltrated the Rapscallion camp, Rockjaw served as their connection to Redwall Abbey, staying hidden and working as a messenger. He himself was contacted by Taunoc.
During Midge, Tammo and Fourdun's escape from the camp, Rockjaw was mortally wounded shielding Midge from a spear thrown by Rinkul; Tammo quickly avenged both Rockjaw and Russa by killing Rinkul with his own spear. Rockjaw then ordered Midge, Tammo and Fourdun to retreat to Redwall while he bought them some time, knowing he was beyond saving. He killed dozens of vermin with his arrows before he was finally surrounded, then made his final stand by tearing the spear out of his side and charging. Tammo, Midge and the rest of the Long Patrol mourned his death.
After his death, Rockjaw appeared in a dream to Russano while he was still an infant, telling him to remember him even when he grows up.
Rockjaw Grang's surname may be derived from the Old English term “Grange”, which means “farmlands”.