I had an interesting idea about there being 2 versions of Spike in
Equestria Girls dimension; because dragons are both animalistic and sapient(?)… The reason why Spike becomes a dog is because, at the time, his dog counterpart was the closest to the portal

So there is a human counterpart of spike

https://www.fimfiction.net/story/297783/equestria-girls-new-dragon-in-school

actually it's already been done. But if you want to do your own take on it you're more than welcome to

6691346

because dragons are both animalistic and sapient

This seems like a very arbitrary distinction, though. I mean, how are dragons more animalistic than say ponies?

6691496
I think what he/she means by animalistic is they (most of them anyway) are much more aggressive and prone to attacking anyone they deem a threat even though that fits ponies and humans to a T.