otherkins and therians aren't a kink, they're people individuals who like to think of themselves as non-human, usually animals but it's possible for them to be robots or AIs too.
also safe search is pretty good nowdays, save for some unpredictable algorithmic fuckup the days of looking up blue waffles and getting hit with diseased vaginas are over
\* Some may object over being called people but i can't think of any other word that wouldn't have me repeating myself
few words of advice:
e621 has a sister site called e926.net that's basically just e621 with a hardcoded rating:safe filter,
and you should always add either order:score or order:favcount at the end of the search because by default it's sorted from newest post to last and new posts can have mistakes including missing solely needed tags or having the wrong rating.
i don't see this and the app is updated :'3nvm it's still experimental for now