Kei-Ko is a gorilla who "speaks" via communicator. In "Magical Pet", she and many other animals are captured by the Dean, who plans on turning them into fuel via special machinery. Witnessing her communicating via communicator[1], Leonard takes her and offers her to Baby Cakes, who wants a pet he can think of as magical. Baby Cakes denies her, but accepts a Bigfoot-resembling Frank instead. While the two are alone, Frank and Kei-Ko bond, and she tells of her desire to go to the Congo. Instead, Baby Cakes has the Dean take her back, but fortunately she's rescued by the Cakeses and Frank when Frank talks Baby Cakes into it and the they bribe the Dean. Fulfilling her wish, they take her to the Congo, where she gleefully roams the lands and is accepted into a family of gorillas.

Kei-Ko is voiced by Cat Power.