"Xenogender is an umbrella term for non-binary gender identities that cannot be fully described through their relation to concepts typically used to describe gender such as masculinity, femininity, androgyny, neutrality, agenrity, or outherinity. Instead, xenogenders can best be described through how they relate to things, beings, or concepts that most people don't think of as having to do with gender, such as animals, plants, things, or concepts. It is sometimes described as any gender that "cannot be contained by human understandings of gender". People who identify as a xenogender may call themselves xenic. The gender quality associated with xenogenders is xeninity. " (Mogai Genders Wiki)

Basically, in short, some people find gender so very confusing (mainly neurodivergent people) so they make a gender they indentify with to feel comfortable.

Neopronouns is what you call the pronouns that come out of xenos, they are mainly used online, so people who use xenos will use He/Him, She/Her or They/Them still.

You can identify with as many xeno's as you want :)

The xenogender flag was created on January 15, 2017 by DeviantArt user Pastelmemer.

The term xenogender was coined by Tumblr user Baaphomett in 2014

(The prefix xeno- indicates some having to do with aliens, which is appropriate as xenogenders are unrelated to human (anthro-) genders.)