A Night in the Lonesome October (1993)

Zelazny manages to cleverly combine Jack (the Ripper), Sherlock Holmes, Dr. Frankenstein, and Dracula together with witches, werewolves, druids and many others in this amusing tale of an approaching confrontation that, on the Halloween of a full-moon, will change the cosmic balance of power between good and evil. Told through the eyes of Snuff, Jack's guard dog, who performs magical calculations in addition to accompanying his master on collecting expeditions into 19th century London. Twists and turns of magical espionage and adventure unfold as this unforgettable tale plays out over the course of 31 lonesome nights in October