This individual was trapped in a malfunctioning airlock aboard Deep Space 9 during his visit to the station in 2369. He was angry and beat against the airlock window while the repair crew under Miles O'Brien tried to free him and the two other passengers, a Human and a Bajoran. They were instructed by O'Brien to "save your energy" and "[w]e'll have you out of there as soon as possible." Later he became infected by the virus and was among the infected treated in crew quarters which were re-built into a hospital. (DS9: "Babel")
For this appearance, the script simply described him as a "newly arrive visitor" and an "N.D. alien".
He was seen on the Promenade when Miles O'Brien gave the newly arrived Tosk a tour. Later he sat at Quark's Bar and was asked by Quark what's bothering him today. (DS9: "Captive Pursuit")
In this appearance, the script simply described this alien as "another depressed customer".
Later that year, he was talking to a female Starfleet officer on the Promenade while the Cardassian Aamin Marritza was imprisoned. Later he witnessed Kainon stabbing Marritza to death on the promenade. (DS9: "Duet")
He returned to the station in 2370, where he was sitting on a bench, socializing in the Promenade near the Odo's security office with a Bajoran. (DS9: "Necessary Evil")
This female visited Quark's Bar in 2375 shortly after Sarina Douglas was brought aboard the station. She participated in several games at Quark's including a dabo game hosted by M'Pella. (DS9: "Chrysalis")