Colour Sergeant O'Cragg was a large, barrel-chested male hare with a loud voice; he was the adopted son of Colonel Gorsebloom, having no memory of his real parents. He was a member of the Long Patrol of the mountain fortress, Salamandastron, under Lord Mandoral Highpeak, and was one of thirty hares recruited by Captain Raphael Granden to accompany Tiria Wildlough on her mission to free the otters of Green Isle from the terror of Riggu Felis and his feral cat army.
Though O'Cragg had the exterior of a no-nonsense, strict and gruff officer, he was actually a gentle and fanciful beast at heart. After the last battle against the cats, Tiria and O'Cragg made plans to watch for the stars of the fallen; specifically, Cuthbert Blanedale Frunk's and Petunia's stars. He and the other hares later escorted Tiria and the rest of the otters to Holt Summerdell, before returning to Salamandastron.