My Life as Dinosaur Dental Floss (The Incredible Worlds of Wally McDoogle #5) - Bill Myers

It was just a little lie. But mishap follows mishap until Wally is chased by bungling terrorist, a SWAT team, the TV news, and the National Guard. It isn't until he risks his life to save his country (and has a little chat with the President along the way) that the madcap misunderstanding finally end. . . And Wally learns that honesty really is the best policy.