I rather wish I hadn't paid full price for this: $25 bucks for a little over 100 pages is way too much. And even at that length, the book feels like a scholarly article pumped up by piling on marginally related information.
Regal shows how the Jersey Devil, a legend that supposedly goes back to colonial days, was manufactured in the early 20th century by a dime museum (they had the monster's corpse!) and sensationalist news accounts (based on mysterious hoofprints found in the snow). The bulk of the slim book is devoted to the Leeds family of the 16th and 17th century, whom the book argues inspired the earlier version of the legend, the "Leeds devil." This is not at all convincing: okay, Leeds' political adversaries accused him of Satanic practices, but as Regal points out, that was par for the course in his time; why should that lead to legends of a monster? We also get lengthy discussions of the era's writings about monsters in general which, while good, again feels like padding.