Jacob Fenn was a physically crippled, but surprisingly able midget  and the business partner of Codringher. He is described as having no legs, disproportionately long arms, a large head and no neck at all. He got around using a motorized chair of some sort. He and his associate ran the Dorian firm known as "Codringher and Fenn" where they dispensed "legal consultations". The firm was in reality just a cover for their illegal interests and machinations. Fenn was essentially the research department of the firm.
Although the witcher was already acquainted with Codringher, Geralt had always assumed that Fenn was fictitious. He was quite surprised to finally make the man's acquaintance, in the flesh. Sadly, their association did not last... One evening, Codringher let his guard down and was mercilessly killed along with Fenn by Schirrú and Nazarian when they forced their way into the agency.
- In the original Polish, he is described as "Karzeł", a human afflicted with dwarfism, instead of "Krasnolud", the dwarven race.