Don Knight

 played Darrin's cousin Robbie in the season eight episode, Samantha and the Loch Ness Monster (1971).

Biography
Don Knight was a stage, film and television actor. He was born as Donald Hartwich Knight on February 16, 1933 in Manchester, England.

Knight began his acting career in theater at the age of eight, appearing in productions of Hamlet, Measure for Measure and Much Ado About Nothing. He was also featured in the play Major Barbara.

He continued his theatrical career, moving from England to Canada and finally to the United States, where he settled in Southern California and participated in the Old Globe Summer Festival in San Diego.

Knight’s acting career eventually branched out when he landed roles in films and television series. He was best known for his "cold killer" roles, but enjoyed playing likeable characters as well.

He essayed numerous roles in the films The Hell With Heroes (1968), The Hawaiians (UA, 1970), Too Late the Hero (1970), Something Big (1971), the remake of Trader Horn (MGM, 1973), Treasure of Matecumbe (BV, 1976) and Swamp Thing (1982).

In television, Knight appeared on episodes of Run for Your Life, The Immortal and Hawaii Five-0. He had recurring roles on Little House on the Prairie and Bonanza. Other guest appearances included Mission: Impossible, The Time Tunnel, Kojak and It Takes a Thief.

Knight was also an ordained minister. After leaving England, he studied for the ministry in Montréal, Canada and Washington D.C. He served as a minister from 1956 until his death.

Don Knight died on August 18, 1997 in Squaw Valley, California. He was 64. He was survived by his wife, Karin Hartwich-Knight, a daughter and son (from his first marriage), his sister and mother.