Yeto
Yeto was a 24th century Klingon mercenary.
In 2370, during a plasma storm that forced the majority of Deep Space 9 personnel to be evacuated, Yeto and T'Kar were hired by the rejected Trill Verad, to steal the Dax symbiont from Jadzia Dax. They traveled to Deep Space 9 aboard the Ekina. He was assigned to guard Julian Bashir in the infirmary after the successful transplant of the Dax symbiont to Verad.
Initially, Yeto mocked the Federation doctor and the unconscious Jadzia, stating that the latter should have fought for her life instead of accepting her fate in order to save her friends. Bashir, who was smitten with Jadzia, yelled at Yeto and sufficiently impressed the Klingon with his "little spark" of rage that he agreed to help the doctor save Jadzia's life.
Yeto quietly watched over the doctor as he revived Jadzia and reassured her that everything would be alright. Shortly thereafter, as Verad wrangled with the moral conundrum of killing Jadzia and taking the symbiont from her by force, Quark attacked T'Kar and feigned injury in the attempt, leading to him being taken to the infirmary with Bashir. As the culmination of Quark's elaborate deception, Bashir was able to knock out Yeto with a hypospray. (DS9: "Invasive Procedures")