(written from a Production point of view)
William Glover (born 1926; age ~94) is the English actor who played the ghost of Jacob Marley in the Star Trek: The Next Generation fourth season episode "Devil's Due". Glover filmed his scenes as part of the second unit on Friday 7 December 1990 on Paramount Stage 8 and had a makeup call at 7:00 a.m.
Glover had previously appeared on such television series as Kung Fu (with Keye Luke and fellow TNG guest star Robert Ito), Fantasy Island (starring Ricardo Montalban and also guest-starring George D. Wallace and Jane Wyatt), WKRP in Cincinatti, Lottery! (with Charlie Brill, Lee Delano, and Bruce French), St. Elsewhere (with Chad Allen, Jeff Allin, Ed Begley, Jr., Robert Costanzo, Norman Lloyd, Deborah May, Jennifer Savidge, Brian Tochi, George D. Wallace, Alfre Woodard, and Jane Wyatt), and Newhart. He also had brief stints on the soap operas General Hospital and Santa Barbera and was one of the many Star Trek performers to appear in the 1986 mini-series Dream West. Among his co-stars in the latter project were F. Murray Abraham, Jeff Allin, Erich Anderson, Lee Bergere, James Cromwell, Michael Ensign, Jonathan Frakes, Alice Krige, Matt McCoy, Glenn Morshower, Fritz Weaver, Noble Willingham, and Anthony Zerbe.
Glover's only feature film credits have been 1978's The Big Fix, also featuring his Dream West co-stars and fellow Trek alumni F. Murray Abraham and Fritz Weaver, and 1983's To Be or Not to Be, with Christopher Lloyd and Paddi Edwards. He voiced Winston the butler in the animated Walt Disney movie from 1988 titled Oliver & Company. In 1991, he co-starred with Rene Auberjonois, Jennifer Hetrick, Tony Jay, Richard Kiley, and Alan Oppenheimer in the made-for-TV movie Absolute Strangers; this is his last known acting project to date.