Scumnose was a rat captain in Cluny the Scourge's horde. Scumnose and Frogblood were in charge of rounding up soldiers to serve under Cluny's command, especially rats, who they considered to be superior, weasels, stoats and ferrets. They managed to get a hundred recruits, pressed-ganged into service under threat of beating or death. Scumnose and Frogblood also led a group of soldiers into scaling Redwall Abbey during the siege.

Scumnose sometimes acted as relay for Cluny's orders and reported news to him. He and Mangefur found Plumpen and his family of dormice and took them prisoners. Scumnose was presumably killed during the final battle for Redwall.