A grounded Alvin begs Theodore to buy him a limited edition skateboard.

During a costume visit to the zoo, Alvin finds himself mistaken for a real Tasmanian devil. Soon, Alvin is stuck in the Tasmanian devil's cage and the real animal, goes home to the Sevilles'. The mix-up creates problems all around, especially when Simon reads that the Tasmanian devil is scheduled for surgery. Can Dave and the boys get to Alvin before the operation?!