Kingenic
Growing up, we never felt very connected with humanity, even though parts of our system might have wanted to (e.g. Ariel, the Little Mermaid). We particularly related to dogs over humans because we grew up with a family dog. Dogs were one of our first-ever special interests, and we would often behave like one or draw ourselves as one, even if we drew our family as humans in the same drawing.
In particular, there was an incident at school at a very young age where I apparently bit another child (I did not remember the biting part and was aware it was odd at the time I didn't remember, but I was aware I had done it). When I was asked why I did it, I said, "puppydogs bite people", and I was told, "Well, you're not a puppydog". I found this very confusing, because I legitimately perceived myself as a dog in that moment.
If stressful but non-traumatic factors led to the creation of our system, it would have involved our sense of detachment from humanity in favor of dogs, and later things like stars, aliens, angels, big cats, rodents, and fictional species.
Even if alterhumanity did not cause any parts of our system, it definitely explains why, in the development of Blue's and Bryan's Superclusters, Blue's Supercluster was much more oriented towards non-humans and animal identities, whereas Bryan's Supercluster has usually had humanoid members who managed part of our identity that were moreso to do with queerness.