I legit don’t understand what otherkin is and no one has given me an actual answer… People keep thinking I’m attacking them but with all due seriousness what is otherkin? What makes you otherkin? How do you know that it’s not just something someone just made up?

seriousotherkin:

Otherkin are human beings who believe that they are, on an integral, non-physical level, not human. 

The most common belief is spiritually oriented, or that one’s soul is fundamentally other than human. 

There are also those whose belief is that the root cause of their otherness is psychological, or that their core psychological identity isn’t human. The cause for this otherness is not known, they do not choose to be other, and they are, as a general rule, not disordered in their beliefs. 

You’ll notice that I am consciously using the term believe, not know. 
This is because there’s no way to empirically prove or disprove, beyond all shadow of a doubt, any of these beliefs. 

This is a matter of people’s core identity never the less, a part of how a person sees themselves, on the most base, most fundamental level, and while otherkin do not demand that others believe what we believe, we are still human beings and deserving of the same fundamental basic human rights and respects as others.