Liz and her friends battle a prehistoric dinosaur with a craving for junk foodEveryone knows W. Reid Elementary has the grossest lunchesand the strangest problems. When piles of junk food start disappearing from the school's cellar, Liz Duffey and her friends brush it off as another unexplainable mystery of life in the Weird Zonetheir nickname for the zany town of Grover's Mill. But when a scaly beast bursts out from underneath the cafeteria, they realize that what they thought was a mystery is a real monster with major hunger pangs!The kids must stop the creature from eating their entire schooland everyone in it. Is there anything this animal won't eat? Liz has an idea, but she may not have time to put her plan into action before becoming a meal herself!