is there truly a sort of universal good or evil that exists outside of the perceptions of humans or other animals/aliens/spirits/etc?

Yeah, it is what I think. In order for humans to perceive good, there must be something perceptible to what they give that name.

Though, to me it seems like any being once they have seen themselves in a mirror or reflection will achieve self perception and many will be able to do it without even seeing themselves directly just by looking at their own body or how they move through existence based on willpower.

Maybe the ego is not only self-perception, but an idea that is formed in the heads of people who tell them who they are supposed to be. And that is formed, mainly through self-perception. Otherwise, we should admit that even animals have ego.