None of the cast or crew members ever expected the show to last as long as it had. Misha Collins (Castiel) has stated that at the one hundredth episode party, someone said, "Maybe we'll see you at the two hundredth!", and everyone laughed at the idea, thinking the show would be long gone by that time. The party for the two hundredth episode of the series took place in October 2014. The 300th episode of the show aired in February 2019.
Jared Padalecki (Sam Winchester) dislocated his shoulder while wrestling with Osric Chau (Kevin Tran). The writers were then forced to make up a story as to why Sam was wearing a sling in the beginning of season ten.
An important aspect of the show's music is classic rock, most of which comes from Eric Kripke's own record collection, although one of his favorite bands, Led Zeppelin, has always been too expensive to license.
There is a particular clock that shows up in almost every episode.