Glaser was a Human man. He served in Starfleet as a security officer aboard the Federation starship USS Enterprise in the 2270s.
History
In 2277, after the Enterprise stopped off at the planet Marris V, Glaser became infected along with most of the crew with a contagious bacterium spread by touch. The infection produced an overwhelming compulsion to spread the infection to others. After Spock developed an inoculation, Glaser was among the first to be cured by James T. Kirk and Spock, along with Linda Chang, Sergeant Galloway, Ryan Leslie, Leonard McCoy, Hikaru Sulu, and Montgomery Scott. (TOS - Star Trek II Short Stories short story: "Wild Card")
Glaser was one of five security officers kept on reserve status to beam down to Kappa Rho IV with Spock. The group transported down after losing contact with an initial landing party that included Galloway, Friedman, and Pavel Chekov. (TOS - Star Trek II Short Stories short story: "Intelligence Test")