Theodore is the child of innocence. He is shy, loving, sensitive, gullible, trusting, naive and cute. In short, he is an easy target for Alvin's manipulations. In fact, Theodore often holds the swing vote between his two brothers' choices of action. Simon appeals to Theodore's better nature while Alvin goes straight to bribery. He is constantly craving snacks and in one episode, tried to eat Alvin's hand because of his hunger. Theodore's signature color is green, and he has brown/green eyes in the film. He also has blond/tan fur in the film. He plays the drums, the guitar, and others. He is the baby of the group and is voiced by Janice Karman, who does Theodore's singing voice.
Alvin and The Chipmunks portrayal
In the 2007 film Alvin and the Chipmunks, he is voiced by Jesse McCartney. In this film, he is having some nightmares between him and Dave. It is also mentioned by Simon that Theodore "Fell out of the tree at birth".