"The 'I am angel/sans/plant/wolf/ kin' bios in 2016 you could directly trace to people on 4chan and KF that were creating these accounts to be incredibly shitty about trans people, and it's still a thing they pull out on twitter from time to time. If you see an 'info' post about catkin going around on twt that's literally a thing created in a 4chan thread to fuck with y'all."

Probably a late response, but thank you for bringing this up! I tried talking about it in a (non-FR) server I was in a few days ago and people thought I was being mean or transphobic despite being trans myself. It made me uncomfortable, so I left. A lot of these animal/object kin identities have origins in 4chan trolling. IIRC the first incident was using "clovergender" as a way to sneak pedophilia and troll Tumblr and Twitter trans communities, and the other kin stuff followed suit.