Place of Origin:Unknown
Weapon: Knife
Death: Asphyxiated by Blaggut
Appears: The Bellmaker
Voice(s): Greg Longridge

Cap'n Slipp was a searat and also the brother of Strapp. He was the former captain of the Pearl Queen after he stole her from Finnbarr Galedeep. However, he and his brother got into an argument, and he was left alone on the Pearl Queen while his crew went to have a party with Strapp on the Shalloo. Finnbarr took advantage of this and threw Slipp overboard, reclaiming his vessel. Slipp tried to swim to the Shalloo and get help, but was betrayed by his brother, who left him to drown and chased the Pearl Queen. He washed up on the shores near Mossflower Woods with former boatswain Blaggut, who also had been left behind. Slipp abused and beat Blaggut often, taking advantage of the simple rat's gentler nature.

The two searats found Mousebabe and Furrtil wandering around in the Mossflower Woods, and took them back to Redwall Abbey, on the pretense of being a carpenter and a cook. Blaggut, much to Slipp's disgust, enjoyed the little ones' company and showed an inclination to retire and be a goodbeast. Slipp, however, had his mind set on finding Redwall's "secret treasure" after being told about it by the Dibbuns, and bullied Blaggut into helping him.

After his first attempt at cooking went horribly wrong, Slipp was told off by Mother Mellus and forced to scrub every dish in the kitchen. He was told off by several other creatures, as well, and held a grudge. Furthermore, he and Blaggut began to be haunted by a "black shadow" (really Brother Simeon in disguise, trying to keep them out of trouble), though Slipp refused to admit the spectre actually existed and kept up his search. They eventually managed to lose Simeon and sneak off during the commotion when the Redwallers were having a singing competition. By this point, Blaggut had convinced Furrtil and Mousebabe to tell him where the treasure was buried, and led Slipp to the spot. However, they quickly discovered the "treasure" was just a toy box buried by the Dibbuns themselves. Blaggut thought it was funny, but Slipp flew into a rage.

Simeon, Mousebabe, Furrtil and Mellus arrived on the scene. Slipp was about to kill the Dibbuns for "tricking" him, but Mellus pounced onto Slipp. Killing the badger, Slipp made a break for it with Blaggut, taking a special badger chalice won by the Dibbuns in the singing competition as his spoils. Once they were in the woods, Slipp suddenly found he was unable to get Blaggut to obey, as the gentler searat was grieving Mellus' death. Slipp destroyed the surrounding woodland shrubbery and beat Blaggut mercilessly in his rage, but Blaggut still refused to move. When Slipp called him a fool, however, Blaggut suddenly got up, forever renounced the ways of the searat and strangled Slipp to death, apologizing as he did so but saying it was necessary to keep others safe from Slipp's cruelty.