His film work includes The Competition, Outland, Up the Creek and Star Trek III: The Search for Spock, as well as a minor (but crucial) part, as a cynical hitman, in the earlier Point Blank. Sikking's film career started in 1955. Sikking starred in the 1992 Fox Network TV movie Doing Time on Maple Drive. He has made guest appearances on many TV series including Perry Mason, Rawhide, Bonanza, The Outer Limits, General Hospital, The Rockford Files, The Bob Newhart Show, Hogan's Heroes, Rich Man, Poor Man Book II, Hunter and Batman Beyond.