Top definition
The shadow monster is the creepy creature from Stranger Things, season 2. It is a huge spider-like dragon that has long arms and a one headed hydra-like head. It lives only in the Upside Down, which is a parallel universe just like the Vale of Shadows from Dungeons & Dragons. The shadow monster acts like a virus, infecting a host that has been in the Upside Down for a certain amount of time.
Mike: "It has got to be the shadow monster! It acts just like a virus that needs to infect a host!"
via giphy
by ohnoMillie October 31, 2017
Happy St. Patties Day!