(covers information from several alternate timelines)
Ensign Michael Parsons was a Starfleet officer in the 24th century, His serial number was AB-487-9011 WGL. He served under Captain Kathryn Janeway aboard the USS Voyager. In 2371, Parsons was among the crew stranded in the Delta Quadrant when Voyager was forcefully brought there by the Caretaker.
Neelix believed that Parsons was possessed by the Komar. The Talaxian's reasoning was that Parsons liked his pejuta hot and with lemon, and that his recent order was for cold Pejuta without lemon, therefore he might not be the same person. (VOY: "Cathexis")
While The Doctor was delusional, later that year, he imagined that he and Reginald Barclay were going to disable the holoemitters in engineering and that Janeway ordered Jarvis and Parsons, who was then assigned to the operations division, to stop them. (VOY: "Projections")
In 2373, Parsons suffered from a microbial infection. The Doctor set up a culture of his glial cells to do an immunogenicity analysis, but was too distracted with his holographic family, so Kes did the tests instead. (VOY: "Real Life")