HUMANS ACT NOT HUMAN: The Scariest Monster That Has 2 Arms 2 Legs and 0 Magic

How many △ do you see? (The Void, 2016)One of the prompts on Prismatic Wasteland's blogging list is: "the scariest monster you can imagine that has 2 arms, 2 legs, and no magic abilities".As cliché as it is, I think it's humans acting in strange ways. Which is why I think cults endure as such common and strong antagonists. A couple of recent examples that spring to mind are Midsommar and even Obsession, or Firefly's reavers. Oh, even The Purge might be a good example.I think the creep factor comes from someone looking normal and relatable, but losing the ability to:predict their behavior or their threat level (i.e. a tick or ticking-time bomb)match behavior to age or profession (i.e. children are the killers)display empathy/sympathy on a human-to-human level (i.e. why don't you care I'm hurting)That last one in particular, when it's expressed as non-supernatural sadism- like in Reservoir Dogs when Mr. Blonde or Midsommar's bear scene or even many slasher films which have many…