Damug Warfang, a Greatrat, was the Firstblade of the Rapscallions, the son of Gormad Tunn and brother of Byral Fleetclaw. Following the death of his father, the previous leader of the Rapscallions, Damug enlisted crafty stoat Lugworm to help him cheat in the fight against his brother Byral Fleetclaw for the right to rule the horde. He also used Lugworm to help him rig the Rapscallions' Throwing of the Sword ceremony to ensure that Damug would have his way in leading his army over land - albeit from the back. He did not like sailing due to a possible fear of it.
Damug was a very cunning and intelligent leader who was not a fool, knowing there were others in his horde that might try to assassinate him. He was afraid of Lady Cregga Rose Eyes, and refused to go near Salamandastron while she ruled there.
Borumm and Vendace, with the help of the traitorous Lugworm, later tried to assassinate Damug; the Greatrat, however, had foreseen the attack and ambushed the would-be assassins in the dark. He sentenced them to life in chains, but they escaped, with several other beasts Damug had punished and chained. Damug sent his Rapmark Skaup after them; when the ferret returned with the prisoners, Damug, in an act of undeniable cruelty, threw them into a river with stones around their necks.
Damug planned to conquer Redwall Abbey, as the ferret Rinkul had seen that the south wall had collapsed. However, Tammo and Midge Manycoats, disguised as vermin seers, informed him of a "better" place to stage the battle, and Damug, being a bit superstitious, followed their advice. He led the Rapscallions to the named battlefield, where they greatly outnumbered the Abbey residents and the hares of the Long Patrol who met them. Damug might have completely wiped out the woodlanders' army, but he ordered his troops to stop fighting and imprison their opponents, preparing to execute Major Perigord Habile Sinistra as an example. During the momentary delay, Lady Cregga Rose Eyes and her army of hares swept in out of the blue; the badger and the Greatrat fell off the ridge, with Cregga killing the Firstblade.