Kot finished serving his Romulan prison sentence in 2370. Soon after, he traveled to Deep Space 9 and attempted to kill Quark. However, the two entered into partnership again. He shot a Yridian partner of Quark's, Ashrock, and took the Rings of Paltriss that Quark had just given to him.
He later took Jadzia Dax and Melora Pazlar hostage and forced them to take him through the Bajoran wormhole and into the Gamma Quadrant. He shot Melora with a phaser, but she was later able to disable the runabouts artificial gravity. Using her Elaysian ability to function in low gravity, she was able to launch herself into him, stopping his escape attempt. (DS9: "Melora")
Background information Edit
Fallit Kot was played by actor Peter Crombie. The name of his species was never revealed on-screen.
In Evan Carlos Somers' original draft of "Melora", Fallit Kot was named Megzie Del. The first draft script of "Melora" initially described the character as "gruff-looking middle-age humanoid alien male." By comparison, in the revised final draft of the "Melora" script, Kot was initially described as "a compact, intense humanoid". 
The scene in Quark's quarters was originally intended to be longer, showing him psychologically toying with Quark. As Somers explained, "Megsy [sic] was going to kill Quark by using the Ceti eels introduced in Star Trek II: The Wrath of Khan, but this variety didn't cause mental vulnerability for mind control [....] Megsy [sic] had Quark pinned and he was going to insert the creatures in Quark's ears. I thought that would be a fitting, torturous end for someone who had caused eight years of suffering. But in the aired version, Fallit Kot just strangles Quark. It's not quite titanic enough." (The Official Star Trek: Deep Space Nine Magazine issue 62)
Of Kot's appearance, Michael Piller commented, "We were doing a story where an alien has to eat, which becomes a pivotal scene where he's feeding, and makeup designed this big kind of handle across his mouth so he couldn't eat. We had to kind of shove the food down his mouth. It was hilarious. We cracked up during dailies." (Captains' Logs Supplemental - The Unauthorized Guide to the New Trek Voyages, pp. 64-65)
The make-up department created Kot's mouth ridge using durable rubber that looked and moved like a piece of flesh. It is considered one of the more unique designs seen in Deep Space Nine. (Star Trek: Aliens & Artifacts, p. 152) Michael Westmore further discussed the design in the DS9 Season 2 DVD special feature "Michael Westmore's Aliens: Season Two". He explained that designing Fallit Kot's make-up was the first time he had an opportunity to aesthetically bridge an alien's face. Kot's makeup consisted of two pieces which were later glued together, giving this alien a unique look when he talks.
In the Worlds of Star Trek: Deep Space Nine novel Ferenginar: Satisfaction is Not Guaranteed, Lieutenant Ro Laren reviews Kot's file, along with those of other individuals considered threats to Quark, after becoming chief of security on Deep Space 9.