Curse of the werewolf boy / by Chris Priestley.

Enhanced descriptions from Syndetics:

For fans of Lemony Snicket, Neil Gaiman, and Nightmares! comes a funny and deliciously creepy, action-packed adventure by acclaimed author Chris Priestley.

Mildew and Sponge don't think much of Maudlin Towers, the blackened, gloom-laden, gargoyle-infested monstrosity that is their school. But when somebody steals the School Spoon and the teachers threaten to cancel their holiday break until the culprit is found, our heroes must spring into action and solve the crime!

But what starts out as a classic bit of detectivating quickly becomes weirder than they could have imagined. Who is the ghost in the attic? What's their history teacher doing with a time machine? And why do a crazy bunch of Vikings seem to think Mildew is a werewolf?

This brand-new series from Chris Priestley, full of delightfully original wit, is perfect for young readers who like their mysteries with a bit of bite.