#forget self-inserts

Hm.... This is a tough one....

So, I feel like both Scott & Nom are the sort to be fairly good at taking care of higher needs pets: Scott because he is a very fastidious sort & isn't likely to be scared away by more difficult relationships (which we see with other people but I am choosing to believe extends to animals as well) if he deems them worthwhile (case in point: Nom). I also feel like on some level, a high enrichment needs pet might be good for Nom, especially as he adjusts to not fighting, as a form of routine & someone/something other than himself to focus on so he doesn't go completely stir crazy with nothing dictating how his day goes & being stuck with his own brain.

I also feel like they'd fit more social pets, something that would enjoy physical contact to at least some degree as well as passive social time just hanging out with its people.

So, on one hand: bird(s).

I honestly kinda like the idea of them having a pair of crows (pair because crows do best with at least one other crow with them, even when they have strong social attachments & interactions with humans or other animals). Like I could see Scott being very attentive with making sure that all the crows' environmental needs were taken care of & them following him around his garden, foraging for bugs while he does watering & weeding. For some reason, I can really just see Nom having a very doting but teasing relationship with them, where they mess with his shit & he then spends a bunch of time figuring out new puzzles for them & teaching them various tricks & vocalizations (since crows are so good at mimicry including human speech). He'd also be great at Mandatory Bird Social Screaming, which is a very amusing image in my head.

With modern au (or any actually realistic au), that does get a little more complicated, since crows are So Much as actual pets & kind of illegal depending on where it is set. To make them work with your modern au, I'd probs actually go with them being wild crows that Scott befriended (because that is Very Much a thing that you can do & Scott would have the patience to do it) & that Nom feeds while Scott's away alongside watering his plants. I would imagine that going something along the lines of Nom being kinda peeved by them at first but becoming Extremely Attached to them & developing a complex relationship with them, very Dad Who Didn't Want A Cat style. Or if they appear after that, the crows befriending both Nom & Scott separately, perhaps without them realizing it at first. But yeah, them being either outdoor semi-pets who just hang around their houses or the "invited themselves to live in one of their houses" sort of situation if you're okay with kinda fudging the reality scale a bit.

Otherwise: a large breed cat.

I'm thinking either a forest cat type, like a Maine Coon, Siberian, or Norwegian Forest Cat, or a breed with more recent wild cat ancestry, like a Savannah or Bengal. All these guys tend to be very social, very smart, pretty to very active, & hecking huge (except for Bengals with are more like average to slightly above average compared to most domestic cats). There is a scale for the level of social & mental enrichment as well as physical activity needed for these cats, with Savannahs being the highest needs (since they will have a wild cat in the last few generations) followed by the Bengal (their wild cat ancestor(s) are further back than Savannahs, but more recent than other domestic cats' on a scale of thousands of years), while forest cats are closer to other domestic cats than wild cat hybrids but still have higher needs than most other domestic cats.

The biggest thing with these guys is that I don't really see Nom or Scott going to a breeder to buy a cat, but that doesn't rule them out. There are rescues that specifically work with wild cat hybrids (as well as cats who are from wild cat hybrid breeders but don't meet breed standards for one reason or another) to find appropriate homes to adopt them so they don't get taken in by someone expecting a chill house cat & wind up neglected (& the adopter experiencing property &/or physical harm from a wildly understimulated cat that is legit part wild animal).

More reasonable, though, would be a forest cat. Purebred forest cats aren't common outside of breeders & purebred rescues, but it isn't uncommon to find cats that are technically just "domestic longhairs" at shelters, but who have very strong forest cat leaning traits to a degree where you can even point to what sort of forest cat they resemble. Like my sibling's childhood cat was very Maine Coon coded in appearance & behaviour, just slightly more dialed back, but the giant kittens I adopted a few years back are so specifically similar to Norwegian Forest Cats that I sometimes wonder if they are actually purebred/half-breeds that got surrendered to animal control because they were too much to handle. (& they are a lot to handle; one actually had to be rehomed to my gran's house out in the country so she could have space to run around outside during the day to burn off energy.)

In any case, my thought with larger, more social, more active cats is that they wind up being somewhere between a cat & a dog with how they feel to care for. Most sorts of dogs don't feel quite right to me for flowersmith (& I admittedly don't have the dog knowledge to tease out which breeds would make more sense to me for them), but I also can't imagine them as a pair having a domestic cat who isn't A Lot & moderate to high needs in a way that isn't just because of anxiety (though probably some anxiety because more intelligent cats tend to be more anxious in one way or another).