In Stranger Things, the Demogorgon is a creature from the Upside Down parallel dimension who menaces the cast in the show's first season. The Demogorgon was immediately an incredibly memorable villain that stuck out in viewers' minds. Over the years since Stranger Things' first season, it has become one of the most iconic and heavily merchandised elements of the series, including a (now-unavailable) appearance in Dead by Daylight. In a series full of memorable antagonists, the Demogorgon is the most likely to stand the test of time.