What production company made season 1 with Monkey Massacre Productions?

The production company that made Stranger Things season 1 with Monkey Massacre Productions was 21 Laps Entertainment.

21 Laps was founded by filmmaker Shawn Levy and became a major television partner on the series. In early development, Dan Cohen, then an executive at 21 Laps, brought the Duffer Brothers’ script to Levy. The company helped develop and produce the show alongside the Duffers’ Monkey Massacre Productions for Netflix.

The question can cause confusion because Netflix is the distributor and streaming service, not the production company named in the answer. Amblin Television is another plausible-sounding choice because Stranger Things draws heavily on 1980s Amblin-style adventure and horror, but it was not the credited co-production partner for the first season. 21 Laps also remained associated with the series across later seasons, making it one of the show’s defining production companies.