Tieflings. The "alignment" section of the 5e PHB (before they decided describing alignments was racist and removed it) read:

Tieflings might not have an innate tendency toward evil, but many of them end up there.

Which is such a powerful storytelling device. It does what sci-fi and fantasy are so often great at: comment on real-world social issues with a step of indirection that makes the story feel less on the nose. Their internal innate selves are indistinguishable from humans, but because they have horns, a devil's tail, and often reddish skin, people assume they're evil and treat them accordingly.

It's an element that is handled so excellently by Erin M. Evans in her Brimstone Angels series:

A woman stood in the doorway opposite the bench, watching Farideh with a wary eye, no subtlety in her distaste. Farideh shifted uncomfortably.

“You waiting for someone?” the woman said after an interminable time.

“My friend,” Farideh said. “He won’t be long.”

“Buying spices from another devilborn.” She sniffed. “Your kind do like to stick together.”

Farideh’s tail flicked nervously. She pulled it closer to lie along her thigh. “My friend’s human, many thanks.”

“Is he now?” Farideh met the woman’s skeptical gaze. Without the ring of white humans were used to, Farideh’s eyes were unreadable. Emotionless. Inhuman. The shopkeeper could stare as long as she liked and Farideh knew she wouldn’t see anything there, not without practice.

“Do you want me to have him show you?” Farideh said. “Or do you want to say what it is you’re getting at?”

Farideh knew perfectly well what the shopkeeper was getting at: she didn’t belong here. Whatever clientele the shopkeeper was used to dealing with, a seventeen-year-old tiefling trying to rein in the tendrils of shadow that curled and coiled around the edges of her frame was not a part of it

Longer excerpt available on author's blog. (It's book 3 of the series, but no significant spoilers here.)

Of course that's only one small part of the characters, but it's done so well. They're well-rounded full people who, like any real human, have to deal with getting through life (in their case, fantasy action adventures) while other people react to them.