Rick and Mortymocked A Nightmare on Elm Streetin the series’ second episode, “Lawnmower Dog,” and the show has kept parodying horror movies ever since, most recently mashing up The Santa Clause and Prometheus in season 9’s “The Last Temptation of Jerry.” Most of these episodes focus on meta gags in the same way the show pokes fun at movies across genres from Total Recall to Freaky Friday. But one episode genuinely leaned into horror and transformed the entire series.