They all provided generally the same information on the creature, though Mythical and Fabulous Creatures only discussed werewolves and didn't speak of the beast. It focused instead on the relationship between werewolves, Christianity and the power of the devil--whether he was behind the lycanthropy and if so, how he went about it. Could he truly transform a man into a wolf or was the wolf-appearance merely an immaterial guise?
This books also spoke briefly about the werwolf's love of female flesh, but also a page (or so) long discussion about a Frenchman named Gilles Garnier. Garnier went to trial for his dealings with the 'Lord of the Forest,' who "gave him the power...to change into a variety of beasts, including a wolf." (South, 273) Though there was no mention of the beast of Gévaudan, I still appreciated the brief discussion on lycanthropy in France for, as I mentioned earlier, there is some speculation as to whether or not the beast was actually a werewolf (and not just an insanely-large and oddly colored wolf).
The other two texts, The Werewolf and Witchcraft, Lycanthropy, Drugs and Disease, were interesting to compare side by side. The information they provided was similar--but only relatively. Witchcraft... describes the Beast of Gévaudan's reign of terror as between the years 1764 through 1767, while Werewolf states that the Wild Beast of Gévaudan was active in 1764 and '65. Makes me curious to inspect the sources of my sources...
Also included in The Werewolf was a lovely drawing of the beast that looks like a cross-breed between a lion, wolf and a large-toothed donkey.