Mojo Missing / Who's the Animal.Mojo Missing: In a moment of generosity, Alvin offers his hat to a fan. However, he soon starts losing his singing and physical skills and believes that his "mojo" has left him along with his hat. He then tries to get it back, but fails every time. The Chipmunks and Chipettes ultimately give him another hat while letting him believe it is his old one and Alvin gets his mojo back. When Alvin discovers the trick, Simon tries to tell him that it is all in his head, but Alvin misses the point and starts believing that he can infuse things that touch his head with his mojo.
Who's the Animal: Alvin is temporarily voiceless. The next day, the Chipmunks go to the zoo disguised as animals and Alvin accidentally gets into a cage while letting free a baby Tasmanian devil due for appendix surgery in the evening. Since he himself is disguised as a Tasmanian devil and is trapped in his costume because he cannot reach the zipper, the zoo personnel mistake him for the baby devil. Fortunately, Simon, Theodore and Dave, who took the real baby devil with them believing that it was Alvin, realize its true nature and bring it back, saving both Alvin and the baby devil's life (whose condition was worsening) in the process.