In Stranger Things canon, the exact total number of Demogorgons in the Upside Down is never given, but the show makes it clear there are many of them as a species , not just one.

One vs many in the show

  • In season 1, there is only one fully grown Demogorgon attacking Hawkins, often called “The Demogorgon,” because it is the only one that crosses over at that time.
  • Later seasons reveal that Demogorgons are a whole species living in the Upside Down and used by humans (like the Russians) and controlled by the hive mind, so there are definitely more than one in-universe.

What we actually see on screen

  • Hawkins in 1983: 1 adult Demogorgon is shown on screen (the main monster of season 1).
  • Russian prison (Kamchatka): the Russians keep 1 adult Demogorgon plus 6 Demodogs (younger Demogorgon stage), so 7 related creatures in that facility.

Fandom and forum discussions

  • Fan discussions often debate whether some attacks in season 1 were done by multiple Demogorgons, but the creators have described it as just one monster roaming Hawkins at that time.
  • Fan wikis and theory posts treat “Demogorgon” as a broader species tied into the Mind Flayer/Vecna hive mind, implying many unseen creatures beyond the ones directly shown.

Simple takeaway

  • On-screen, you clearly see a handful of individual Demogorgons and Demodogs (a single main one in Hawkins, plus the Russian specimens).
  • In the wider story, there are many Demogorgons in the Upside Down, but the series has never given a precise number.

Information gathered from public forums or data available on the internet and portrayed here.