The Werewolf of Fever Swamp by R.L. Stine

In the book, Cassie believes in werewolves and that the swamp hermit is the werewolf.In the episode, Grady realizes that Will is the werewolf when the lunar eclipse covers the full moon which causes the werewolf to partially revert to Will. In the book, Grady realizes that Will is the werewolf due to seeing that the werewolf has broad shoulders and a thick neck just like Will has.Will is portrayed more sympathetically, and Grady says 'Poor Will' when he sinks into the bog and drowns.The Swamp Hermit is implied to have been killed by the werewolf in the episode, while he survived in the book.The episode reveals that Will killed the Swamp Hermit's wife and children.In the episode, Grady's encounter with The Swamp Hermit is less pleasant as the hermit inversely kidnaps Grady after he gets caught in the hermit's trap and the man drags him back to his shack, believing that Grady is the werewolf.Cassie O' Rourke is omitted from the episode entirely.Vandal breaks into the Tucker's house at night instead of jumping out at Grady in the book.In the episode, the dog is named Vandal, not Wolf.Dogs don't howl at the full moon, or disappear at midnight, or turn into werewolves. Everyone is convinced that the dog is a monster, but Grady knows better.

Could Grady's new dog be responsible for some of the midnight mischief? He does sort of resemble a wolf, and he appeared out of nowhere. And the almost-human howls that make him sit straight up in bed each night.

Now Grady can't stop thinking about the spooky hermit who chased him and his new friend Will while they were exploring the swamp behind his new house. Then there was the scary shadow lurking behind the tree and the spooky sounds coming from the swamp. That's for sure! First came the horrific howls during the night.

Grady and Emily didn't want to move to the Florida swamps in the first place, but their mom and dad – both scientists – said that it would be 'an adventure they would never forget'.

The Werewolf of Fever Swamp by R.L. Stine