Star Trek first introduced fans to the Klingons in the 26th episode of the first season of TOS, "Errand of Mercy". The Federation, in a desperate attempt to thwart an invasion by the warring Klingon Empire, sends the Enterprise to Organia to offer protection. Captain Kirk and Mr. Spock run into Commander Kor. (picture)
The Klingons would show up several more times, but the most notable are, Koloth, season two, episode 15 "The Trouble with Tribbles", and Kang in the season three episode 7 "The Day of the Dove".
Klingons would not been seen again until the opening sequence of Star Trek: The Motion Picture(1979)
This time Klingons had a "spine head" look, and spoke Klingon. This was a huge upgrade from the 60's TV look, yet fans seemed OK with it. This would not be the first, or last time that the Klingon appearance changed. In 1984, Star Trek 3: The Search for Spock gave us Commanded Kruge.
His look was altered from ST:TMP, now Klingons wear a "turtle head". In 1986 Star Trek: The Next Generations introduced Worf. This look would stick around for a while, and became the accepted Klingon look.
Star Trek 5:The Final Frontier changed that look a little, giving us, what I call "biker" Klingons.
In 1991, Star Trek 6: The Undiscovered Country gave us General Chang
his head was more smooth, and he has an eye patch bolted to his head. The look remained the same through Deep Space Nine (1993) Voyager(1995),and Enterprise (2005).
Voyager gave us B'Elanna Torress.
Speaking of Enterprise, season four episode's "affliction" and "Divergence" explained why the Klingons changed between TOS and TNG. It was a super virus that caused the traditional Klingon "ridge" to disappear, leaving them looking more human. I'm not sure that we needed this explanation, but now it's out there. This would be why the Klingons seen in TOS, looked more like TNG Klingons when they appeared on DS9 second season episode "Blood Oath".
Klingons wouldn't be seen again until 2009. JJ Abrahms re-booted the franchise with Star Trek (2009) and the Klingon look changed again, this time we got a "lizard" head with gold piercings I kinda like this version of Klingons, I think the piercings could be a rank system of some kind.
Then the Klingon upgrade that would break the internet, and cause massive fan hatred. In 2017 Star Trek Discovery introduced us to T'Kuvma, the leader of a religious sect.
The producers of Discovery went all the way back to 1979, and used production sketches of the Klingon's that was originally meant for ST:TMP .
This sketch is from The Star Trek The Motion Picture Sketchbook, does it look familiar? It was decided, after fan anger, that the Klingons shaved their heads during times of war. The addition of hair made them look more like fans expectations.
Discovery would explore Klingon culture in a much deeper ways that had been done before. We see 24 great houses, and learn that they each have specific "skills" that they are exceptional at. L'Rell belonged to House of Mo'Kai, the house of spies, they surgically altered Voq. He appeared as a human, and had all the memories of Ash Tyler.
Dennas, held the council seat for the House of D'Ghor, does that Klingon "bling" look familiar?
So what does all of this really mean, it means that Klingons all look different. I think it's safe to say the Klingon we see on Discovery are what true pure breed Klingons looked like. After conquering and mating with alien races, plus the "super virus" they became more like the classic "turtle head" Klingons. We don't know what The introduction of the "cure" had on the genetic make up of the race, not the cultural repercussions of appearance, or "ridge" size. The real question is, Does size matter to Klingon's?
