Which episode of "Rick and Morty"  aired unannounced on April 1, 2017 and was replayed every half hour from 8pm to 12am ET, as part of Adult Swim's annual April Fools' prank?
The Rickshank Rickdemption "The Rickshank Rickdemption" is the first episode in the third season of the American animated television sitcom "Rick and Morty", and the twenty-second episode overall in the series. It was written by Mike McMahan and directed by Juan Meza-Leon. The season three premiere first aired unannounced on Adult Swim in the United States on April 1, 2017 when it was watched by 676,000 American households. On the first day of its original broadcast, "The Rickshank Rickdemption" was replayed every half hour from 8pm to 12am ET with improved ratings, as a part of Adult Swim's annual April Fools' Day joke.
South Park (season 18) The eighteenth season of the American animated sitcom "South Park" premiered on Comedy Central on September 24, 2014 with "Go Fund Yourself", and ended with "#HappyHolograms" on December 10, 2014, with a total of ten episodes. The season featured serial elements and recurring story lines, which "The A.V. Club" noted as an experimentation with episode-to-episode continuity, in which the episodes "explore the consequences of the boys' actions [week to week], allowing the plots to be motivated in part by their attempts to dig themselves out of a hole".