Most fans consider "The Trouble with Tribbles" an undisputed Star Trek classic. The show's creator and at least one star would disagree.
David Gerrold wrote the script for "The Trouble with Tribbles." He recalls working with Star Trek's creator.
“Gene Roddenberry had no sense of humor and working with him was a joyless exercise," Gerrold says.
Gerrold was 23 at the time and still in college. "The Trouble with Tribbles" was his first professional sale. He has since gone on to become an award-winning science fiction author.
Gerrold recalls, “My original conception was, ‘Aliens are always scary. What if they’re cute but we don’t realize they’re dangerous? What if you had white mice or gerbils that got onto the Enterprise and got out of control?’
"My attitude was that it would be whimsical but that we would have a serious threat.”
Gerrold credits producer Gene L. Coon with saving the now classic episode.
“He knew you had to balance gravitas with lightheartedness—that you can’t save the galaxy every week,” Gerrold says. “Roddenberry never understood that.”
It was Coon who encouraged Gerrold to flesh out his script, then titled "The Fuzzies." The name of the creatures was later changed to Tribbles and the episode title changed to match. This was to avoid legal problems with H. Beam Piper's science fiction novel Little Fuzzy. The episode ended up butting against a different science fiction novel instead.
As the script went through revisions, more and more jokes made their way into the episode.
“I never intended the episode to get that funny until we got into the development,” Gerrold says. “I realized there was the possibility of a lot more humor.”
Some of the humor can be credited to the cast rather than to Gerrold. Several gags were not in Gerrold's shooting script. Gerrold credits the impending Labor Day weekend as well as director Joseph Pevney.
“I think it was just a case of ‘Let’s just party out on this one," Gerrold says. “[Story consultant] Dorothy Fontana said, ‘Let’s hope Joe directs because he knows comedy.'"
And so an unexpected fan favorite was made. Now 50 years later, "The Trouble with Tribbles" remains a hit.