@Cynicallia: Those are all some very good questions!
Originally, the nose spikes were going to be trait that was unique to Dargon and certain other older Hexxilians. I didn’t think much of it at the time, I just thought it looked cool and it helped set him apart from the younger ones. I really didn’t think much about age differences when I first created these characters, aside from Hornex having a dad. All the females were going to have long hair, as I used to think of it as a more feminine trait. Females also usually wore more clothing, following the tradition of designs for Sonic characters and classic cartoon characters in general. Also, all Hexxilians were just lighter or darker shades of brown, regardless of age or health.
In the new universe, the whole species is getting an overhaul! I was thinking the snoot spikes are a result of a slightly uncommon genetic mutation, though a decent amount of the population has this trait. You’re just not guaranteed to inherit it, even if both parents have them. For sexual dimorphism, I was thinking males would just be a teeny bit bigger than females; but not by a significant margin. They all need to be able to climb up trees and other surfaces effectively after all! Although all of them have “manes” now, the hair on females is still generally longer for cultural reasons, and it tends to grow faster on them too. I was also thinking of giving them a wider range of skin colors; like yellow, orange, pink, light red, amber, hazel, and bronze. Though some of them, like Hornex and co., will still be brown, as that is also a skin color for them. A few of them may even be gray, black, white, or even a very pale blue or green, though these colors are much less common and aren’t considered full natural. In regards to age, they definitely have a peak. Once they’re past their prime, they do begin slouch and degrade a bit. Though, they do have ways to mitigate the effects of old age, and some individuals do age a bit slower than others. When it comes to clothing, it honestly differs from tribe to tribe and even clan to clan. Some may allow and/or like to accessorize with jewelry, or more fancy and exotic materials for decoration, while others might only accept clothing or accessories that are only practical and nothing else. However, some who were either raised in or grew up in or near “outsider” settlements may adopt styles from these places to either ‘fit in’ better or simply because they like to wear such things. Like I said, it varies from tribe to clan to even the individual at times. I guess certain things, like capes or badges or even a specific piece of armor or clothing, have to earned in order to wear them. How to earn that honor, again differs between groups.
I know this is a lot of info to take in, but there is a lot more stuff I’m planning to incorporate into their lore and I didn’t want to go overboard with just this one comment. I figured to at least give you enough of it to answer at least some of your questions for the time being. The story and lore for it is still a work in progress, and that is just ONE of a bunch of stories I want to work on! It can be a bit overwhelming trying to juggle between different projects, especially when you add things like a job and certain routines into the mix!
Now, there's an interesting thing to think about. How do you plan on showing age differences among Hexxilians? It looks like daddy has snoot spikes, and I didn't see those on any of the other characters' designs. Do the spikes come as they get older, or is that something that is entirely unique to him, for other reasons? Do the females show any differences? Perhaps their colors become more bright or faded at different points in their life? Do adults continue to grow as long as they remain healthy, or is it normal for them to eventually reach a peak like humans do, and then begin to shrink or slouch during their latter years? When you redesign them some day, do you think they will be more accepting of clothing, or will they continue to lean towards only wearing functional gear, such as belts and bandoliers? If clothing becomes more prominent, would different age groups wear different things; for example, earning armor as a sign of becoming an adult, or acquiring capes or badges to show their accomplishments?