Eddie Munson was the breakout star of Stranger Things season 4. But the show’s tradition of killing a beloved new character continued. Eddie didn’t survive the season – but how old was he when he died?
Although Eddie was a high school student, he was older than his classmates. It was revealed in the first episodes of season 4 that Eddie was supposed to graduate high school in 1984 and he was sure he was finally going to do so in 1986. Though neither his age nor his birthdate is mentioned in the show, it’s implied that Eddie was around 20 years old at the time of the events of season 4.
As stated earlier, Eddie died in the Upside Down when trying to lure the Demobats away. But in the final episode of season 4, Eddie’s uncle, Wayne, was seen putting up missing person papers in search of his nephew, and the age listed on the posters is 17 which means that there is a mistake regarding Eddie's age.
Although it could be a mistake from the production crew of Stranger Things, there can be an explanation for this.
Considering Eddie’s rebellious personality and record, it’s possible he went missing in 1983 (for whatever reason), and his uncle was reusing the missing person posters from that time. Also in season 4, it was revealed that time is frozen in the Upside Down with Nancy finding out that it’s still 1983 there. As Eddie died in the Upside Down, he technically died in 1983 and not 1986. Thus his age on the poster fits as he would have been 17 years old in 1983. Still, it does not explain why the poster had what would technically be the right age for him.
The creators of Stranger Things can use this mistake in their favor in season 5, either by explaining more about the Upside Down or revealing more about Eddie's past.