In 2268, Mara was part of the Klingon crew and Starfleet crewmembers aboard the USS Enterprise that while under the mind control of an unknown alien entity were fighting a no win battle. She was very worried that she would be violated by the Starfleet crew. She assisted Captain Kirk in negotiating a peaceful end to the conflict by taking him to Kang and supporting Kirk's theory that an alien was controlling both forces. (TOS: "Day of the Dove")
Mara was played by actress Susan Howard. She was the first featured character to portray a Klingon female in the series. The script described her as "an especially striking woman" as well as possessing "icy intelligence."
Although the reference was never mentioned on screen, it is very possible that Mara was the mother of Dax, son of Kang, from DS9: "Blood Oath". Mara was not mentioned in that episode and it is unknown if she was still alive at the time of her husband's death in the episode, which took place more than a century after their last appearance.