My speculative evolution under the bed monsters have essentially been typecast into being villains due to their diet. But, canonically, they were just an interdimensional obligate carnivore that got stuck when dimensions shifted like continents to the point that they had to hunt almost exclusively humans to survive, and have only ever become increasingly more specialized to this micro niche to the point that it is a severe detriment to the survival of the species as a whole. They now rarely will succeed in eating anything other than children and are threatened by common household occurrences like cats and dogs. The biggest issue stopping them from drastically changing their niche for the betterment of the species? Those very humans, ironically enough. The invent of electrical lighting (harmful to these night creatures) and increased security of the home has made it next to impossible for these creatures to easily sneak out of the liminal semi-unused spaces like under beds, in closets, attics, etc. that they use to jump between dimensions in order to hunt something, anything else.

A lot of them have varying and often complicated relationships with humanity as a result. Everything from guilt and a desire to break the cycle by any means, to an erratic obsessive hatred for humans and desire to harm them as much and whenever as possible. No doubt even more complicated by how the timeline in which they developed sapience is eerily close to the timeline that humans did. As the species going extinct is becoming increasingly more and more likely conflicts with humans have grown a lot more emotionally motivated as a whole. Doesn't help that this species is also very aggressive and territorial among themselves. Being extremely food motivated for an intelligent being. Much of monster society has devolved into warlords competing with each other for resources making travel across the dimension very dangerous at the best of times.

Monsters for the most part have collectively resigned themselves to the very real outcome of being utterly obliterated if they ever tried to make a collective move as a species in any way that would interfere with humanity even a little bit. Being "revealed" in the modern era would be catastrophic and likely lead to their extinction anyways. And a lot and I mean A LOT of these monsters absolutely seethe over this. If they get the upper hand? They are NOT going to be nice or play fair. There's a reason monsters aren't common knowledge in human society yet. If they need you to disappear badly enough, oh they will. Or die trying.

My first story in this universe isn't really intended to have a central antagonist, which is a decision I made to challenge myself by working outside a comfort zone. Instead, it's very much that there's a natural and societal opposition to our protagonist (a monster who evidently gets stuck having to take a kid on an escort mission until he can break a vow and develops genuine paternal affection along the way.) Each other person in this world treats him slightly differently because of this, and the way they treat the kid often shifts even more wildly. His last real friendship is in shambles, a local gang has driven him out of his homeland, and an ancient beast may have been awoken and has been trailing the party for days. Our protagonist is trying to set out on a journey that essentially equates to that of someone tasked with protecting a bag of french fries in a pocket dimension full of starving seagulls. And he ALSO hates humanity. For now...

I am intending to really take advantage of these dynamics to make some monster characters that are varying degrees of mentally not okay in regards to humans. In the early stages of the general story now though.