Michael Jan Friedman is the author. It's okay, and he captures Chaney, Jr.'s performance well enough. The prose is kind of clunky (not that I'm expecting a
Wolf Man novel to be lyrical), but it fits well into the films, taking place between
The Wolf Man and
Frankenstein Meets the Wolf Man.
He makes attempts to explain some of the weird things about the film, like why Bela turns into an actual wolf, while Chaney maintains a more human form.
The biggest complaint I have is that not much happens. There's no transformation until almost 140 pages in, and it's only a 235-page book. That isn't to say that it needs lots of transformations to be interesting, but not a whole lot happens until then.
Like
Shadow of Frankenstein, some of the descriptions of gore took me out of the world of the Universal Monsters. It doesn't go into extreme territory with that, but definitely more than the movies. But, to be fair, that'd be true with any blood at all. Of the three I've read,
Shadow is still my favorite.