10 Background Star Trek Actors More Important Than You Think
4. Uncredited Actors As The Original Series Klingons In Deep Space Nine
When Star Trek redesigned the look of the Klingons in 1979 with the release of The Motion Picture, many fans believed they would never get an explanation for these changes.
Flash forward to the Deep Space Nine/The Original Series crossover episode Trials And Tribble-ations and we get to see Worf, a modern Klingon, react to their appearance. This only deepened the mystery as Worf seemed disgusted by the sight of them and proclaimed, "We do not discuss it with outsiders." Nowadays, thanks to Star Trek: Enterprise, we now know that the true reason why the Original Series Klingons looked so similar to humans was because a genetically modified virus, created using human DNA, got loose in Klingon society, but at the time, this became one of the most hotly debated mystery's in Star Trek.
These three, uncredited actors from the '60s didn't know it, but almost three decades later, they would be the first ever official confirmation that the Original Series look of the Klingons was truly canon, which opened the door for countless fan-theories before being explained in Enterprise.