What do you find generally creepier, "fully grown" underage characters or adult characters that look like children?

Examples? No wait, no, nevermind.

I feel like the former is more inherently creepy whereas you can have some relatively harmless context explain away the latter.

So I've been watching In/Spectre and the main character in that is kinda the "adult who looks like a child" a bit. But it's just that she's a small lady and, like, sometimes small people exist. She doesn't act like a child or have childlike expressions. So I in that context, it's not really creepy.
Now when it's the "they was permanently made to look like child because of magic/a curse/etc, but also aren't they kinda hot?" that stuff is creepy.

I feel like with the former, generally the character's age isn't the focus. Like the character designs are what they are (and they can most certainly be creepy regardless of age) but the age is incidental due to the demands of the setting and pretty much everyone the character interacts with is underage.

Where with the latter it generally feels very explicit why a character was designed this way and why their age is being heavily signposted, to make it 'ok' to be creepy, so I'll give it the slight edge.

Neither are great.

But having a kid character that's barely dressed, yet they slap on a "they're 18!" excuse in the English version, that's especially not great.

The answer would depend on the context. Like are we talking about a slice of life type of show or something more fanservicey.

@csl316: I'm giving a strong disapproving glance at Tokyo Mirage Sessions for this one (as much as I like that game).

Fully grown underage characters is the worst for me, because most times it goes into echi or fanservice territory, while still trying to dodge the problematic implications.

Are elves underage? Are Leprechauns underage? Arefairies underage? Are pixis, nixies, brownies and hobgoblins underage? Are the various stories of 'hidden folk' or 'forest spirits all about underage people? REALLY? Seven continents, thousands of cultures, millions of stories are really just a conspiracy of perverts?

So, that is where I think these questions goes off the rails. If the story or narrative says a being is not a child, then isn't it...not a child? Yes, let's argue the points in reasoned discussion, but to say "Nope, the matter's settled ist all perverts telling pervert stories" is a bit much to conclude. I think this is a question that CAN be argued, and there is not a definitive conclusions either way.

It is not like the 20th century invented the concept that "fey spirits and little people", these concept of spirits, pixies, brownies, and such small folk have existed in stories for seven thousand years old. So, it is problematic to suddenly say, "Yeah, but we modern people REALLY know what these ancient storytellers intended with their stories." I think these questions brings up interesting point both ways. In fact, there are hundred of research papers and books that can be written about these stories, and some of them should question what these little people represent? What would folklorists do at Oxford University without such questions?!

Even today, I kinda doubt that people that are deep within anime fandom and most truly contribute to anime's zeitgeist really give a shit about Yoko Littner being 14-years-old.

And I'll just leave this here: