Unidentified 'Trope'?

[EXAMPLES INCLUDED AT THE END]

There is a certain kind of story that I love. But I've yet to find any name for the trope, or genre, or whatever it is that connects the stories. This is a problem as it makes looking for more stories like this a real chore. It surprises me that the connection doesn't exist considering the litany of fairly specific tropes you can find on TVTropes.com.

Now, onto the trope (I'm not even confident it qualifies as a "trope", really, but it's the best word I've got for it.) I'm calling it, for now, "Secret Species."

The name comes from secret societies. However, unlike those, the behaviours and cultures exhibited by the individuals in these groups oft come from a different biology, odd circumstances, or they come from, or lived in, an extremely different location (extraterrestrial, extradimensional, extratemporal), as opposed to differing ideology.

These groups are often non humans hiding among humans. Though sometimes the opposite can be true. Usually these people have more power in one way or another over those in the larger society in which they hide. Naturally, most modern vampire and werewolf stories fit in to this Secret Species 'trope'. However power is not a necessary part of that 'trope', merely a common occurrence in it.

Similarly, in some circumstances, the hiding isn't necessary either.

In most of these stories the main character(s) see themselves inducted from the larger species into the smaller. Though sometimes the entire subspecies came from the larger.

Most of the time if it is a group of individuals with less than five people, it does not count, wiping most HIEs out of the equation. HIEs that include five or more people but remain completely human and make no effort to hide themselves are also out.

This is the best I can do to describe it, but it's not quite accurate. In a few cases some of the above is quite untrue for some of the following examples and yet I feel that that each one of the following fits in this, previously unnamed, 'trope'. My hope is that by writing this blog and grouping what stories I can think that fit, perhaps together we can identify this thing. If you think you have a story that fits, then please, by all means, suggest it. It may not fit after all but that will help too. The more stories I can say are and are not qualified, the closer I'll be to identifying just what it is about these stories, and find more like 'em.

Some examples of this 'trope':
Ship of the Line: Forever After Earth
Five Score Divided by Four (and most, if not all, of its spinoffs)
The Girl with the Lyre Tattoo
The Support Group For HiEs
MLP Time Loops
A Home for Slayers
Jedi Harris
The Lord of Light
Stories in the PonyEarthVerse
Bronygeddon
Black Queen, Red King
The Chaotic Touch of Harmony
Maximum Ride
Animorphs

"'You bucking let him go or I’m going to sheer off your horn, break your legs, and leave you to the wolves!' I screamed at the phone" - Man, without thinking, refers to pony biology in a 5s/4 side fic. Can't Stop Now by PingSquirrel