Writing The episode was the first professional work of writer
David Gerrold, and went through a variety of drafts before it reached the screen. Because his typewriter used a less common, smaller size font, an approved
screenplay version needed to be reduced by twenty pages before filming. Gerrold had been a fan of science fiction since he was a child. When
Star Trek was first broadcast, he was concerned that it might turn into something similar to
Lost in Space, which he has described as "one full-color hour of trash reaching into millions of homes". His first story outline was sent in to
Star Trek after his agent suggested that he wait until the shows started to air under the theory that the show might drop an existing episode in favor of a better script. The story was entitled "Tomorrow Was Yesterday" (not to be confused with the
Star Trek episode "
Tomorrow Is Yesterday") and concerned the
Enterprise coming across a
generation ship which had degenerated into a two-tier class system. It went on to say that it would require a budget larger than that available to television, but would have made a good film treatment. Coon offered to meet with Gerrold and explain what they were looking for, because they were not purchasing scripts at that time. In preparation for the second series submission, by January, Gerrold had put together five premises to pitch. He had his best hopes on two treatments called "Bandi" and "The Protracted Man", but decided to submit his fifth story despite Coon's earlier dismissal of the idea. The idea was based on the introduction of
rabbits in Australia in 1859, whose population grew extraordinarily fast owing to a lack of predators. The initial premise placed the story on a space station to avoid the ecological damage that the creatures would have on a planet. However, Gerrold's agent was concerned that requiring a miniature of the station to be built as well as the additional sets would cause it to be too expensive for a single episode. Because of his agent's comments, Gerrold modified the pitch to place the action on a colony planet instead. This pitch included the plot points such as the creatures getting into a poisoned grain storage, but omitted the Klingons; and Cyrano Jones was called Cyrano Smith. The five pitches were submitted by Gerrold's agent in February 1967, and received a response in June. At the time the show had already purchased too many scripts for the second season, but story editor
D. C. Fontana suggested that they should purchase the story and assign it to a staff writer as it was better than some of the other stories they already had. At the time that Coon got in touch, Gerrold had just been employed at
CBS as a typist working on scripts such as the pilot of
Hawaii Five-O. As soon as he got the response, he quit the job. Gerrold and Coon met once more, and revealed that the network had recently made a request for more episodes based on other planets. Coon told Gerrold to work up a further pitch. and moved the action from planetside to a space station. During a visit to the set, Gerrold had the opportunity to speak to Leonard Nimoy and ask his advice on how to write for Spock and was allowed to watch the
dailies from each day's shoot of the episode "
The Doomsday Machine" which was being filmed at the time. This version of the story was entitled "A Fuzzy Thing Happened to Me...", He offered Gerrold a chance to write the script himself, by promising not to hand it to another writer for a month. However, Coon made it clear that he was not offering Gerrold a script assignment, but was giving him the option of submitting a draft. Gerrold turned around the first draft script in two and a half days. Both Coon and associate producer
Robert Justman gave feedback on the script, and pointed out a few gaps such as there needing to be some way in the plot for the crew to discover that Darvin was a Klingon agent. The following draft had Cyrano Jones discover that Darvin was an agent, which Coon thought was not "punchy" enough. It was then re-written so that the fuzzies were allergic to Klingons. Both Gerrold and Coon thought the idea was "trite... shtick... hokey" and "had been done before". On a further visit to the set, Gerrold was called into Coon's office. He was informed that he needed to change the name of the fuzzies, as the legal department was concerned about similarities in the name with
H. Beam Piper's 1962 novel
Little Fuzzy. He subsequently came up with a variety of alternative names. Through a process of elimination, he ended up with the name "tribble". Gerrold's submitted script was within the standard page count for an episode, but, when it was retyped for distribution by the production's mimeo department, it ballooned from 60 to 80 pages due to Gerrold's having used a typewriter with 12-
pitch Elite rather than the 10 characters per inch Pica standard of the TV and film industry. This meant that some twenty pages needed to be cut from the script. Scenes which were cut from the script included the
Enterprise chasing after Jones in his vessel, and resulted in the scene where Kirk has tribbles tumbling onto him while in the grain locker. Gerrold felt that this enforced editing process "tightened up the story and made for a better series of gags". During script development the Kellam de Forest Research firm cautioned that the tribbles and the events involving them strongly resembled the Martian
flat cats in
Robert A. Heinlein's 1952 novel
The Rolling Stones, and suggested that the rights to the novel should be purchased. Gerrold became concerned that he had inadvertently plagiarized the novel which he had read fifteen years before. Coon phoned Heinlein, who, according to Gerrold, only asked for a signed copy of the script and later sent a note to Gerrold after the show aired to thank him for the script. The producers liked the resulting script so much that Gerrold was later tasked with re-writing the script for "
I, Mudd". Heinlein’s own recollections were at odds with this account. In his authorized biography Heinlein said he was called by Gene Coon who gave him a "sob story" about the issue and asked him to waive claim to the "similarity" to his flat cats. Heinlein states he agreed because he’d just been through one costly plagiarism lawsuit against
Roger Corman and did not wish to embroil himself in another "chump's game". He had misgivings upon seeing the actual script but let it go, an action he later regretted: "If that matter had simply been dropped after that one episode was filmed, I would have chalked it up wryly to experience. But the 'nice kid' did not drop it; 'tribbles' (i.e. my 'flat cats') have been exploited endlessly… Well that’s one that did 'larn me.' Today if J. Christ phoned me on some matter of business, I would simply tell him: 'See my agent.
Filming The use of live animals to represent the tribbles was immediately ruled out. According to Gerrold's account, as their similarity to Heinlein's flat cats was not yet discovered, the inspiration for the form of the tribble instead came from a fluffy keyring owned by Holly Sherman. The design came from
Wah Chang, but they were individually sewn by Jacqueline Cumeré. She was paid $350 to sew five hundred tribbles from synthetic fur and stuff them with foam rubber. Six ambulatory tribbles were made using the mechanisms of walking toy dogs, which were quite noisy and required the dialogue to be looped in during editing. Other tribbles were created by Jim Rugg out of
beanbags for when it was required for one to sit on a person or object, and the breathing tribbles were hollow with surgical balloons inserted. The sale at
Christie's auction house in 2006 included tribbles from this episode as part of a larger
Star Trek sale. Because of the synthetic fur technology of the 1960s, relatively few original tribbles exist as of 2010 because the fur fell out over time and they went bald. An original tribble was sold at auction in 2003 for $1,000. Filming began during the second week of August 1967. Three temporary sets and a portion of corridor were constructed for specific use in this episode, which included the large trading post set. The chairs in that set were a problem, as the set designers wanted 24 matching chairs and decided that
folding ones would not do.
John M. Dwyer sourced them from a local company, but the numbers required meant that they had to be pulled out of showrooms from all over the county. When it came to the fight scene in the episode, Dwyer warned director
Joseph Pevney not to damage the chairs. That scene was filmed twice after a cameraman with a handheld camera wandered onto the set. Gerrold had expected that scene to be cut at some point during production, as he thought that William Shatner would not agree to it. He said that Shatner was the "consummate professional and I believe he was eager to show off his comic abilities". The scene was later described as "solidifying 'The Trouble with Tribbles' in the pop culture lexicon". Pevney was pleased with the outcome of the shoot, calling the episode "a delightful show from beginning to end". Pevney was one of the two most prolific
Original Series directors alongside
Marc Daniels, and directed fourteen episodes of the show. The cast responded favorably to the script. Nichelle Nichols was particularly pleased as it allowed Uhura to be a woman and took her off the bridge. The special effects design for the K-7 Space Station in the episode was based on actual 1959 design by
Douglas Aircraft Corporation for the space station.
Casting William Campbell had previously appeared in the first season episode "
The Squire of Gothos" as
Trelane. In "The Trouble with Tribbles", he portrayed the Klingon Captain Koloth. At various points
Star Trek creator Gene Roddenberry claimed it was his intention to bring back Koloth during the third season of
The Original Series, as Kirk's recurring Klingon adversary. Some internal production documents contradict this story. Although Koloth returned in
Star Trek: The Animated Series, Campbell did not voice the role. entitled "
Blood Oath". At the time of casting, William Schallert had just finished filming the
ABC sitcom The Patty Duke Show. He described himself as not a fan, and had not read any science fiction since 1948. He thought that the role of Nilz Baris was just another guest spot, and considered Baris to be just "a rather stuffy bureaucrat, not the most appealing character". He did not remember the character's name, only learning it when he first attended a
Star Trek convention at a hotel near
Los Angeles Airport, as the fans called it out when he entered the lobby. Michael Pataki, who portrayed the Klingon Korax, went on to play Karnas in
Star Trek: The Next Generation first season episode "
Too Short a Season".
Charlie Brill portrayed the Klingon agent Arne Darvin. ==Reception==