Chapter Eight: The Mind Flayer - S2-E8
Factual error: When El arrives, Hopper rifle has a picatinny rail, inaccurate for the time period.
Chapter Eight: The Mind Flayer - S2-E8
Factual error: Joyce asks Will if he remembers when he was 8 and she bought him that giant box of crayons for his birthday - the 120 pack. Will is 13 in the show, so when he was 8, it was 1979. There were only 78 colors available in 1979 and the 120 crayons box was not available until 1998, almost 20 years later.
Answer: The body was fake, made by the scientists at Hawkins Lab in an attempt to cover up his disappearance and the existence of the Upside Down.