“Carnival Row” is a rarity among television fantasies these days because it did not begin life as a comic book, novel, film or other existing property. It’s what’s called an original.

But there’s original and then there’s — well, you get the idea. The series, whose eight-episode season arrives Friday on Amazon Prime Video, reanimates bits and pieces from different branches of the fantasy genre into a glum and lumbering beast that only occasionally sparks into life.

That description could also fit one of the show’s monsters, a golem-like creature that figures in the investigations of a detective named Rycroft Philostrate , known as Philo and played without much evident enthusiasm by Orlando Bloom . He slogs through the grim and rainy streets of a London-like, Victorian-ish city where humans uneasily coexist with various humanoid species identifiable by their horns, snouts or hooves. Philo’s opposite number, and interspecies love interest, is a winged fairy (or fae) with the equally ostentatious name of Vignette Stonemoss (Cara Delevingne) .

Philo and Vignette inhabit a world, created by René Echevarria (“The 4400”) and Travis Beacham (a screenwriter on “Pacific Rim”), that probably sounded better in the pitch meetings. It has a strong medieval-magical component, with wintry fortresses, butchery gruesomeness reminiscent of “Game of Thrones” and an assortment of creatures like those in the “Lord of the Rings” and “Grindelwald” franchises.