My son has specifically requested "funny" chapter books, and I'm having trouble finding them. As reference, he classifies the Tales of a Fourth Grade Nothing series and The Best Christmas Pageant Ever as funny. He loves Dan Gutman (My Weird School and others), but they're so short that he'll read them in a single sitting. Not the worst thing ever, but it would be nice to have longer options.
Any suggestions? (He is finishing second grade but reads much higher -- Harry Potter, Percy Jackson, etc.)