Wanna give it a go with Zyvv~ Adding them below to keep things clean
1 - They don't know why, but they've always been a magnet for animals. Something about them just makes non-aggressive animals relax in their presence, and they have an easier time approaching agitated animals, which turned out to be something pretty useful during their early days in the Inquest, as interns were the ones who had to handle and feed specimens.
2 - That affinity isn't mutual, however. In fact, not only Zyvv never really cared about animals, but they also found any creature that was too big (read: taller than their waist, adjusted for age) to be scary. They got over that fear through forced exposure during their three years in the Inquest, but they still never cared for animals as more than "acceptable price for important research", at least until Mardis.
3 - They're intersex! Zyvv presented and was socialized as a boy until puberty, when they suddenly developed in a feminine way. It was a genuine surprise, but after the initial concern for the unexpected change (and some medical reassurance that it was rare but totally fine), they realized they actually preferred themselves that way and grew more confident, even learning to take care of their looks a bit and enjoying it. (They prefer neutral pronouns because gender is not something they bother with, but they don't mind being perceived as feminine. They also kept their name because their father picked it.)
4 - Zyvv always struggled a lot with making friends and bonding with people in general, as they were pretty anxious and shy. In early education Zyvv had some outgoing classmates who considered them a friend, but then they had no friend during the three years in their mother's "care". During both apprenticeship and College in Rata Sum, they did have some friendships, but it was all pretty superficial because of their anxiety (boosted by their mother's abuse), so they remained closed-off and lonely overall.
5 - In spite of the lack of actual friendships, people did tend to like having them around! Zyvv was always hardworking, generally nice (chronic people-pleaser), and particularly non-competitive, so no one had reason to start conflict with them and neither did they. Still, that mostly translated to classmates and krewemates taking advantage of them (taking the blame for stuff they didn't do was a bit of a pattern in their life).
6 - While they avoid conflict at all costs, if particular buttons are pressed Zyvv can become a bit of a mean brat and surprisingly headstrong about it. It takes even more to bring them to the limit where they actually become angry, but that happened so rarely they can count all instances on their fingers, at least before their escape from the Inquest.
7 - They're generally quiet and never start casual conversations, but if given the chance, they will yap all the yapping they never yapped.
8 - Due to thier mother's krewe being often out on field research as they were tasked with the study and categorization of Brisban's flora with potential medicinal effects, Zyvv learned a bunch about with living away from civilization. They eventually despised the idea of it, like most things tied to their mother, but in retrospect that experience served them very well.
9 - They never had an actual romantic relationship. Not for lack of trying, as they had three potentially-nice relationships in the making, but they all went sideways due to various reasons, ending before they became serious enough. They did have a "thing" that lasted four months when they were an intern in the Inquest, but that was strictly for pure mutual benefit.
10 - Zyvv considered their father's krewe as family. Pliff was a good father, but a bit in over his head when he came back to Rata Sum with an oopsie progeny in a sling. After he found a krewe to work for, most of them with experience helped him out where he had no idea about what he was doing. Until more than half of the krewe died suddenly seven years later, including Pliff, Zyvv spent most of their time with them. The little progeny usually quietly observed and learned from the krewe, occasionally asking questions or even helping as they could (mostly nothing of importance given the krewe developed and built lab defense systems, but little Zyvv was extremely dutyful in what they were allowed to do).
11 - Zyvv's hair is butt-length. Being the practical type, their mother Nijji preferred to shave her head in order to minimize waste of time and safety hazards both out in the field and in the lab, and she did the same to Zyvv in preparation for the first field trip following their sudden arrival. Zyvv, who to that point had their hair at shoulder length and always anxiously fidgeted with them, took the umpteenth radical change so badly that Nijji allowed them to keep short haircuts. After returning to Rata Sum for their apprenticeship, Zyvv let their hair grow out, and the unexpected changes of their body gave them the confidence to try styling it themselves. To this day, they never really cut their hair (besides tiny cuts to keep the ends healthy and even), as it's a small but important source satisfaction for Zyvv, allowing them to look as little as possible like their mom or as she wanted them to be.
12 - Zyvv doesn't look much like their mom (closest thing is their ear shape and size), taking a lot more from their father's side (specifically their late grandmother, as Pliff always said). If Nijji hadn't been the one to pop them out, she would have probably claimed Zyvv wasn't hers (she still kinda tried to claim that when the Peacemakers brought them to her after Pliff's death).
