"I was having dinner with one of the writers and we sort of realised, 'We've done a Halloween episode and a Thanksgiving episode and we skipped over Christmas,'" Aguirre-Sacasa told The Wrap. "As soon as I realised that, I was like, 'We're doing a Christmas episode!'"
Because shooting for Part II had already begun, it was decided that the Christmas episode would be a stand-alone episode.