Ron Glass, whose extensive TV credits included the beloved Firefly, has died of respiratory failure, according to The Wrap. In more recent years, Glass was known as the religious and sage Shepherd Book on Joss Whedon’s short-lived space Western, a role that he reprised in the feature film Serenity. However, Glass’ career spanned decades, and his other iconic part was that of Sgt. Ron Harris on the long-running Barney Miller. He spent eight seasons on the sitcom, and shortly thereafter he became Felix Unger on The New Odd Couple. Glass also did voice work, and his intonations will be known to Nickelodeon fans as Rugrats’ Randy Carmichael.