Little is known about the Old Rabbit (including his name), but he was presumably an escaped slave from the kingdom of Malkariss, and had been driven half mad by his time there. He appeared to be ancient in age and had a wispy white beard. Everything he said was about death, doom, and destruction, except when he mentioned the abandonment and/or murder of the former members of Slagar's Gang. He also knew firsthand the horrors of slavery.
In exchange for a sack that he used as a cloak, the Old Rabbit gave Matthias a token from Loamhedge Abbey, a small stone carving in the shape of a mouse.