Frankenstein is creature made from body parts of dead men and is named after his creator, Dr. Victor Frankenstein. He was given life from lightning and ran away from his creator because of his appearance. Frankenstein, or "Frankie" as he's called by Bufkin and Bigby Wolf, was animated by Nazis during World War II. Bigby fought the monster (in a reference to the 1943 film Frankenstein Meets the Wolf Man) when he and a squad of Allied soldiers stormed the castle where the experiment was being performed. The monster's still-animated head is kept in the Business office in the Woodlands building where Bigby chats with him from time to time. He often has phantom thirst and is given drinks by Bufkin, though the last time this happened, the bottom of his cage rusted out.
Frankie is Bufkin's dear friend and ally, and teams up with him and the others trapped in the Business Office when they discover that they're stuck with Baba Yaga. He is also good friends with the Magic Mirror.