This is a companion piece to the Netflix series, which I have seen maybe an episode or two of, though I have read and enjoyed all of the graphic novels. But I have always liked bestiaries and similar collections of monsters and creatures, so seemed worth a read. This was an enjoyable enough work, but it felt rather thin. There's obviously a fair bit of overlap between the graphic novels and the show, so many of the creatures were familiar; and for those, it felt like this work added little that was not already described in the primary work, and I assume this is the case for creatures unique to the show as well; needless to say, I feel like a companion work should go a bit beyond what is already known, or what is the point?
This thinness can be further seen in how this book is presented as an in-universe object, a work that Hilda has supposedly acquired and written in. But the voice of the primary writing is hardly different from Hilda's voice (even if she occasionally critiques the book), there's no in-universe author listed, and Hilda's notes and sketches fill space that would otherwise be conspicuously blank. None of this is to say that the book is bad, just that it is nothing particularly special either.