Goosebumps: The werewolf of fever swamp

There's something horrible happening in fever swamp. Something really horrible. It started with the strange howling at night. The there was tha rabbit, torn to shred. Everyone thinks Grady's new dog is responsible. After all, he looks just like a wolf. And he seems a little on the wild side. But Grady knows his dog is just a regular old dog. And most dogs don't hawl at moon or disappear at midnight, or change into terrifying creatures when the moon is full. Or do they?