Parem was a Romulan officer accidentally phased by an interphase generator being tested aboard his ship.
When Lieutenant Commander Geordi La Forge and Ensign Ro Laren were also accidentally phased by the same device, he attempted to kill them rather than let the secret of interphase technology fall into Federation hands. He was pushed through an outer wall of the USS Enterprise-D by La Forge in 2368 while trying to kill Ro Laren. (TNG: "The Next Phase")
Parem was played by actor Brian Cousins. He may have actually been the vessel's commanding officer, since his crewmates Mirok and Varel had reported that the captain was dead.