Walter Koenig's Sole Star Trek Writing Credit Was For A Spin-Off That Cut His Character

Walter Koenig, who played Ensign Pavel Chekov in Star Trek: The Original Series, penned one of the earliest adventures for the franchise's spin-off, Star Trek: The Animated Series. However, Chekov was not part of the animated version of the show, replaced instead by an alien named Arex due to budget constraints. The episode, titled "The Infinite Vulcan," had Koenig writing about a giant clone of Spock who nearly kills the original.

Koenig found the experience of writing the episode, with its primitive animation and the addition of talking vegetables, to be unenjoyable. Despite the negative experience, Koenig would later return to Star Trek and go on to write for other shows, including an episode of Land of the Lost.