Mr. Arthur Ketch was one of the top agents of the [[British Men of Letters]]. As a part of the organization, Ketch undertook wet work for the London Chapterhouse and is an expert in weapons, both traditional and magical. He is described by [[Lady Antonia Bevell]], with whom he had a relationship, as a psychopath. He kills monsters and humans alike without compunction.
He wears finely tailored suits, and had a distinctive cross [[Tattoos|tattoo]] on his hand, which
he removed after he faked his death and went underground from the British Men of Letters. He usually rides a [[Mr. Ketch's Motorcycle|Norton Commando Motorbike]], but he is later seen driving a [[Mr. Ketch's Car|Continental Flying Spur]] which holds his weapons arsenal while in the United States.
He is killed by [[Mary Winchester]], but is resurrected by a [[Resurrection Charm|powerful charm]] sewn into his body which he received from [[Rowena]] when she was captured by the British Men of Letters a few years prior. Afterwards, he decides to become a mercenary hunter under the alias "Alexander," killing monsters all over the world for a fee provided by a certain sort of clientele. He is also staying incognito knowing that the British Men of Letters would execute him for desertion.