(written from a Production point of view)
Kirk Raymone, aka Kirk Raymond, is the actor who played Duur in the Star Trek: The Original Series second season episode "Friday's Child". He later appeared as a Cloud Guard #1 in the third season episode "The Cloud Minders".
He filmed his scenes for "Friday's Child" between Wednesday 24 May 1967 and Monday 29 May 1967 on location at Vasquez Rocks and at Desilu Stage 10, and his scenes for "The Cloud Minders" on Wednesday 13 November 1968, also at Stage 10.
Raymone went on to appear in the classic 1977 science fiction film Close Encounters of the Third Kind, starring Teri Garr. The following year, he appeared in the Vietnam War drama Coming Home.