Entities are monsters that roam in The Backrooms, but how did they get there and why are they there? I have some theories about this;

1. Insanities are just humans who lost it in one of the oddball levels.

2. Deathmoths are just moths that have evolved to be able to survive longer in The Backrooms.

3. Partygoers are humans that got infected with a undiscovered disease that may be in Level Fun, and Partypoopers are people who tried to fight the disease once they got infected.