Full Moon Fever

Full Moon Fever is the twenty-second book in the Goosebumps Series 2000 book series. It is preceded by The Haunted Car and followed by Slappy's Nightmare.

The cover shows an unspecified beast in ripped pants with the full moon in the background.

Plot
On Halloween night, two friends named Robbie and Alesha, go trick-or-treating around town. They reluctantly go to the home of one of their nastiest teachers, Mrs. Eakins. When they arrive at her home, however, they are surprised to find that the usually mean Mrs. Eakins is being so friendly. Mrs. Eakins generously gives them both full-size candy bars which the two gobble up on the way back.

The next morning, Robbie discovers that he is completely coated in thick hair, just like a werewolf. Robbie can't talk and finds that he is hungry all the time, frighteningly enough, for living animals. Robbie finds Alesha and the two flee into the woods nearby, away from the police who are pursuing them.

They worry that they have succumbed to a mythical illness called "Full-Moon Fever," which turns anyone who looks at the full moon into ravenous, snarling beasts. Robbie and Alesha go to find Robbie's grandfather, who told them about the disease the night before, only to discover that it is merely an old legend and that it isn't real.

The two go on a journey through the woods to find a cure -- only to be captured by a circus ringleader who turns them into circus freaks. They escape the circus and then deduce that it must be the fault of Mrs. Eakins.

They go to her house and discover that the large candy bars she gave to them were actually cursed, and that she is a witch. They eat many "Cure Bars", which were lying around the house and hope that they will cure them. However, Robbie takes another look at the label and discovers that they actually say "Curse Bar", meaning that they have just likely permanently cursed themselves.

Trivia

 * This book's title is a reference to the Tom Petty album Full Moon Fever.
 * The French cover looks like 2 werewolves wanting a cure bar.