Two Metaphor headcanons specifically about paripus:
1.) They're fuzzy. Not furry exactly, but covered in a fine soft velvety coat that's not really visible from a distance. Usually it matches their head hair, but if you look closely you might see very subtle patterning on some. That's all on that one, I just think it'd be neat. Anyway,
2.) They often join multiple families into a single unit and raise the kids communally, to the point where a paripus pal might introduce you to several moms and dads of theirs that are just as much their parents as their blood relations. Sometimes they forget which parents actually produced them, because it doesn't really matter. Sometimes they couldn't even tell you which of their siblings are related to them by blood. It serves a twofold purpose: first, it just feels nicer to have a home full of activity and laughter and warmth, and second, it's safer in a society where they have an unfortunately high casualty rate to have a lot of spare parents for the kids