Brown Jenkin is a rat-like creature with a human-like face who is a familiar to the witch Keziah Mason.
Brown Jenkin is "a small white-fanged furry thing", "no larger than a good-sized rat", which for years haunts the witch house and the town of Arkham in general, "nuzzl[ing] people curiously in the black hours before dawn".
|“||Witnesses said it had long hair and the shape of a rat, but that its sharp-toothed, bearded face was evilly human while its paws were like tiny human hands. It took messages betwixt old Keziah and the devil, and was nursed on the witch’s blood—which it sucked like a vampire. Its voice was a kind of loathsome titter, and it could speak all languages.||„|
|~ HPL, "The Dreams in the Witch-House"|
When Walter Gilman managed to kill Mason Jenkin replied in kind by burrowing though his chest and eating his heart.
Brown Jenkin's bones were later found with those of Mason and a small child by workers taering out a slanting wall.
Behind the Mythos
The origins of Brown Jenkin are subject to debate. Perhaps the most popular theory is that he is the child of Keziah and Nyarlathotep, the Lovecraftian deity she presumably serves. This is rather likely, considering that Lavinia Whateley mated with Yog-Sothoth, and that in The Lurker at the Threshold (posthumously published and co-written with August Derleth) there is a quote that reads: "'She affirm'd, and her good neighbours likewise, that it had been borne to her, and took oath that she did not know by what manner it had come upon her, for it was neither Beast nor Man but like to a monstrous Bat with human face.'" Another theory, proposed by Weird Tales columnist Kenneth Hite, is that Brown Jenkin was a higher dimensional servitor of Nyarlathotep who was rewarded as being a familiar. However, as he was in the third dimension, he could only appear as a third-dimensional interpretation of what he was (this being similar to the vistas of Hyperspace in the story).