In Aang's canon, he reincarnates a lot. In his first life, he saved this magical animal's life, and since then, this animal guide has reincarnated with him every time to be a friend and look out for him. The animal guide doesn't really demonstrate any kind of personality of its own besides that of an affectionate and slightly-smarter-than-usual-animal.

My question is, is it okay for Aang to have an animal that is that reincarnated animal guide? Like a stray dog or something?