Gegis was a Ferengi.
In 2377, he assisted Nunk in a failed attempt make a profit by attempting to kidnap Seven of Nine in order to acquire her for her Borg nanoprobes to sell. This was attempted by having Gegis re-program a hologram of Reginald Barclay to persuade USS Voyager to travel through a geodesic fold in order to capture Seven of Nine.
The attempt failed when the real Barclay was able to fool him into closing the fold before Voyager entered. (VOY: "Inside Man")
Gegis was played by Frank Corsentino.
According to the Star Trek Encyclopedia, 4th ed., vol. 1, p. 301, Gegis was a technician.