Because “Star Trek” is set in an ultra-professional environment — on board a military-run, government space vessel — the characters all have to be on their best behavior. They adhere to a strict code of formalism and address each other by rank. The vast bulk of characters on “Star Trek” belong to Starfleet or another equally formal governmental military institution. As such, when a free agent or informal character enters the show, they often flit about the Captains and Lieutenants, gently mocking their stuffiness.
Or, in the case of the famous episode, “The Trouble with Tribbles” (December 29, 1967), an adventurer like Kirk (William Shatner) finds himself utterly annoyed by a mission to protect something as commonplace and unexciting as a grain shipment. The dreaded tribbles of the title are cooing balls of fur with voracious appetites. To the diplomats on a space station, the grain is valuable. For Kirk, he doesn’t much care, but he’s required to care because its his job. The comedy from “Tribbles” stems from Kirk’s stone-faced embarrassment. That, and the fact that the tribbles are weird little critters.
Starfleet stuffiness also stands out when a laidback, outrageous character swoops in for an episode. One might recall Trelane (William Campbell), the goofy Squire of Gothos. Or perhaps the lascivious, cackling Harry Mudd (Roger C. Carmell) who, in the episode “I, Mudd” (November 3, 1967), locks Kirk and company into a room with hundreds of silly androids. The Enterprise crew has to dance and cavort and overact to — get this — confuse the androids to death. It’s amusing to see them out of character.