Wikipedia
"#HappyHolograms" is the tenth and final episode in the eighteenth season of the American animated television series South Park. The 257th episode overall, it was written and directed by series co-creator and co-star Trey Parker. The episode premiered on Comedy Central in North America on December 10, 2014. It is the second part of the two-part season finale which began with the previous episode, " #REHASH". The episode makes multiple references of earlier episodes over the season as well as previous seasons while mainly lampooning the trend of culture constantly making trending topics with no actual relevance. It also lampoons news events of the death of Eric Garner, the shooting of Michael Brown, the sexual assault allegations against Bill Cosby, and the use of celebrity holograms. YouTube celebrity PewDiePie appeared as himself, continuing his story line from the previous episode.