Robin has a long and varied history when it comes to guest spots. He appeared with William Windom on Murder, She Wrote, and then as the following characters on Babylon 5: Hedronn, Na'Kal, Na'Tok, and Coplann. He appeared in Voyager as - of all characters - Valen in "The Void". In 1997, he appeared as Mr. Paul Bowman in The Lost Word: Jurassic Park and then in 1999 as Sarris in Galaxy Quest.
Robin's official website.